Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.
Proteins found in ribosomes. They are believed to have a catalytic function in reconstituting biologically active ribosomal subunits.
The small subunit of eubacterial RIBOSOMES. It is composed of the 16S RIBOSOMAL RNA and about 23 different RIBOSOMAL PROTEINS.
The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.
The two dissimilar sized ribonucleoprotein complexes that comprise a RIBOSOME - the large ribosomal subunit and the small ribosomal subunit. The eukaryotic 80S ribosome is composed of a 60S large subunit and a 40S small subunit. The bacterial 70S ribosome is composed of a 50S large subunit and a 30S small subunit.
The large subunit of the eubacterial 70s ribosome. It is composed of the 23S RIBOSOMAL RNA, the 5S RIBOSOMAL RNA, and about 37 different RIBOSOMAL PROTEINS.
The large subunit of the 80s ribosome of eukaryotes. It is composed of the 28S RIBOSOMAL RNA, the 5.8S RIBOSOMAL RNA, the 5S RIBOSOMAL RNA, and about 50 different RIBOSOMAL PROTEINS.
The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)
The small subunit of the 80s ribosome of eukaryotes. It is composed of the 18S RIBOSOMAL RNA and 32 different RIBOSOMAL PROTEINS.
Ribosome inactivating proteins consisting of only the toxic A subunit, which is a polypeptide of around 30 kDa.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.
A process of GENETIC TRANSLATION, when an amino acid is transferred from its cognate TRANSFER RNA to the lengthening chain of PEPTIDES.
Peptide Elongation Factor G catalyzes the translocation of peptidyl-tRNA from the A to the P site of bacterial ribosomes by a process linked to hydrolysis of GTP to GDP.
Intermediates in protein biosynthesis. The compounds are formed from amino acids, ATP and transfer RNA, a reaction catalyzed by aminoacyl tRNA synthetase. They are key compounds in the genetic translation process.
A process of GENETIC TRANSLATION whereby the formation of a peptide chain is started. It includes assembly of the RIBOSOME components, the MESSENGER RNA coding for the polypeptide to be made, INITIATOR TRNA, and PEPTIDE INITIATION FACTORS; and placement of the first amino acid in the peptide chain. The details and components of this process are unique for prokaryotic protein biosynthesis and eukaryotic protein biosynthesis.
Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.
A cinnamamido ADENOSINE found in STREPTOMYCES alboniger. It inhibits protein synthesis by binding to RNA. It is an antineoplastic and antitrypanosomal agent and is used in research as an inhibitor of protein synthesis.
A group of uridine ribonucleotides in which the phosphate residues of each uridine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.
A multiribosomal structure representing a linear array of RIBOSOMES held together by messenger RNA; (RNA, MESSENGER); They represent the active complexes in cellular protein synthesis and are able to incorporate amino acids into polypeptides both in vivo and in vitro. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
Protein factors uniquely required during the elongation phase of protein synthesis.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
The small ribonucleoprotein component of RIBOSOMES. It contains the MESSENGER RNA binding site and two TRANSFER RNA binding sites - one for the incoming AMINO ACYL TRNA (A site) and the other (P site) for the peptidyl tRNA carrying the elongating peptide chain.
Constituent of 50S subunit of prokaryotic ribosomes containing about 3200 nucleotides. 23S rRNA is involved in the initiation of polypeptide synthesis.
The sequence at the 5' end of the messenger RNA that does not code for product. This sequence contains the ribosome binding site and other transcription and translation regulating sequences.
The production of PEPTIDES or PROTEINS by the constituents of a living organism. The biosynthesis of proteins on RIBOSOMES following an RNA template is termed translation (TRANSLATION, GENETIC). There are other, non-ribosomal peptide biosynthesis (PEPTIDE BIOSYNTHESIS, NUCLEIC ACID-INDEPENDENT) mechanisms carried out by PEPTIDE SYNTHASES and PEPTIDYLTRANSFERASES. Further modifications of peptide chains yield functional peptide and protein molecules.
A protein found in bacteria and eukaryotic mitochondria which delivers aminoacyl-tRNA's to the A site of the ribosome. The aminoacyl-tRNA is first bound to a complex of elongation factor Tu containing a molecule of bound GTP. The resulting complex is then bound to the 70S initiation complex. Simultaneously the GTP is hydrolyzed and a Tu-GDP complex is released from the 70S ribosome. The Tu-GTP complex is regenerated from the Tu-GDP complex by the Ts elongation factor and GTP.
A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).
A codon that directs initiation of protein translation (TRANSLATION, GENETIC) by stimulating the binding of initiator tRNA (RNA, TRANSFER, MET). In prokaryotes, the codons AUG or GUG can act as initiators while in eukaryotes, AUG is the only initiator codon.
Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.
A process of GENETIC TRANSLATION whereby the terminal amino acid is added to a lengthening polypeptide. This termination process is signaled from the MESSENGER RNA, by one of three termination codons (CODON, TERMINATOR) that immediately follows the last amino acid-specifying CODON.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Electron microscopy involving rapid freezing of the samples. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.
The largest ribonucleoprotein component of RIBOSOMES. It contains the domains which catalyze formation of the peptide bond and translocation of the ribosome along the MESSENGER RNA during GENETIC TRANSLATION.
Protein factors uniquely required during the initiation phase of protein synthesis in GENETIC TRANSLATION.
One of the CYCLIC PEPTIDES from Streptomyces that is active against gram-positive bacteria. In veterinary medicine, it has been used in mastitis caused by gram-negative organisms and in dermatologic disorders.
A protein phytotoxin from the seeds of Ricinus communis, the castor oil plant. It agglutinates cells, is proteolytic, and causes lethal inflammation and hemorrhage if taken internally.
An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.
Constituent of the 60S subunit of eukaryotic ribosomes. 28S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.
Any codon that signals the termination of genetic translation (TRANSLATION, GENETIC). PEPTIDE TERMINATION FACTORS bind to the stop codon and trigger the hydrolysis of the aminoacyl bond connecting the completed polypeptide to the tRNA. Terminator codons do not specify amino acids.
A species of gram-negative, aerobic, rod-shaped bacteria found in hot springs of neutral to alkaline pH, as well as in hot-water heaters.
Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
Immature ERYTHROCYTES. In humans, these are ERYTHROID CELLS that have just undergone extrusion of their CELL NUCLEUS. They still contain some organelles that gradually decrease in number as the cells mature. RIBOSOMES are last to disappear. Certain staining techniques cause components of the ribosomes to precipitate into characteristic "reticulum" (not the same as the ENDOPLASMIC RETICULUM), hence the name reticulocytes.
A transfer RNA which is specific for carrying phenylalanine to sites on the ribosomes in preparation for protein synthesis.
Peptide Elongation Factor 2 catalyzes the translocation of peptidyl-tRNA from the A site to the P site of eukaryotic ribosomes by a process linked to the hydrolysis of GTP to GDP.
Factors that utilize energy from the hydrolysis of GTP to GDP for peptide chain elongation. EC 3.6.1.-.
A transfer RNA which is specific for carrying methionine to sites on the ribosomes. During initiation of protein synthesis, tRNA(f)Met in prokaryotic cells and tRNA(i)Met in eukaryotic cells binds to the start codon (CODON, INITIATOR).
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Acyltransferases that use AMINO ACYL TRNA as the amino acid donor in formation of a peptide bond. There are ribosomal and non-ribosomal peptidyltransferases.
Proteins obtained from ESCHERICHIA COLI.
Enzymes that catalyze the hydrolysis of ester bonds within RNA. EC 3.1.-.
Constituent of the 40S subunit of eukaryotic ribosomes. 18S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.
Proteins that are involved in the peptide chain termination reaction (PEPTIDE CHAIN TERMINATION, TRANSLATIONAL) on RIBOSOMES. They include codon-specific class-I release factors, which recognize stop signals (TERMINATOR CODON) in the MESSENGER RNA; and codon-nonspecific class-II release factors.
A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)
Proteins found in any species of bacterium.
An antibiotic isolated from the fermentation broth of Fusidium coccineum. (From Merck Index, 11th ed). It acts by inhibiting translocation during protein synthesis.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
An antitumor antibiotic produced by Streptomyces sparsogenes. It inhibits protein synthesis in 70S and 80S ribosomal systems.
The sequential set of three nucleotides in TRANSFER RNA that interacts with its complement in MESSENGER RNA, the CODON, during translation in the ribosome.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The rate dynamics in chemical or physical systems.
An antibiotic first isolated from cultures of Streptomyces venequelae in 1947 but now produced synthetically. It has a relatively simple structure and was the first broad-spectrum antibiotic to be discovered. It acts by interfering with bacterial protein synthesis and is mainly bacteriostatic. (From Martindale, The Extra Pharmacopoeia, 29th ed, p106)
Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.
An oligosaccharide antibiotic produced by various STREPTOMYCES.
A strongly basic peptide, antibiotic complex from several strains of Streptomyces. It is allergenic and toxic to kidneys and the labyrinth. Viomycin is used in tuberculosis as several different salts and in combination with other agents.
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
Ribonucleic acid in fungi having regulatory and catalytic roles as well as involvement in protein synthesis.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Compounds which inhibit the synthesis of proteins. They are usually ANTI-BACTERIAL AGENTS or toxins. Mechanism of the action of inhibition includes the interruption of peptide-chain elongation, the blocking the A site of ribosomes, the misreading of the genetic code or the prevention of the attachment of oligosaccharide side chains to glycoproteins.
Ribonucleic acid that makes up the genetic material of viruses.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.
A semi-synthetic aminoglycoside antibiotic that is used in the treatment of TUBERCULOSIS.
Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.
Nucleic acid structures found on the 5' end of eukaryotic cellular and viral messenger RNA and some heterogeneous nuclear RNAs. These structures, which are positively charged, protect the above specified RNAs at their termini against attack by phosphatases and other nucleases and promote mRNA function at the level of initiation of translation. Analogs of the RNA caps (RNA CAP ANALOGS), which lack the positive charge, inhibit the initiation of protein synthesis.
A prokaryotic initiation factor that plays a role in recycling of ribosomal subunits for a new round of translational initiation. It binds to 16S RIBOSOMAL RNA and stimulates the dissociation of vacant 70S ribosomes. It may also be involved in the preferential binding of initiator tRNA to the 30S initiation complex.
A directed change in translational READING FRAMES that allows the production of a single protein from two or more OVERLAPPING GENES. The process is programmed by the nucleotide sequence of the MRNA and is sometimes also affected by the secondary or tertiary mRNA structure. It has been described mainly in VIRUSES (especially RETROVIRUSES); RETROTRANSPOSONS; and bacterial insertion elements but also in some cellular genes.
Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.
An antibiotic produced by the soil actinomycete Streptomyces griseus. It acts by inhibiting the initiation and elongation processes during protein synthesis.
A type of endoplasmic reticulum (ER) where polyribosomes are present on the cytoplasmic surfaces of the ER membranes. This form of ER is prominent in cells specialized for protein secretion and its principal function is to segregate proteins destined for export or intracellular utilization.
An antibiotic produced by Streptomyces lincolnensis var. lincolnensis. It has been used in the treatment of staphylococcal, streptococcal, and Bacteroides fragilis infections.
A bacteriostatic antibiotic macrolide produced by Streptomyces erythreus. Erythromycin A is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50S ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins.
A component of eukaryotic initiation factor-4F that is involved in multiple protein interactions at the site of translation initiation. Thus it may serve a role in bringing together various initiation factors at the site of translation initiation.
Constituent of the 60S subunit of eukaryotic ribosomes. 5.8S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.
A family of small RNA viruses comprising some important pathogens of humans and animals. Transmission usually occurs mechanically. There are nine genera: APHTHOVIRUS; CARDIOVIRUS; ENTEROVIRUS; ERBOVIRUS; HEPATOVIRUS; KOBUVIRUS; PARECHOVIRUS; RHINOVIRUS; and TESCHOVIRUS.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
A multisubunit eukaryotic initiation factor that contains at least 8 distinct polypeptides. It plays a role in recycling of ribosomal subunits to the site of transcription initiation by promoting the dissociation of non-translating ribosomal subunits. It also is involved in promoting the binding of a ternary complex of EUKARYOTIC INITIATION FACTOR-2; GTP; and INITIATOR TRNA to the 40S ribosomal subunit.
A cytosolic ribonucleoprotein complex that acts to induce elongation arrest of nascent presecretory and membrane proteins until the ribosome becomes associated with the rough endoplasmic reticulum. It consists of a 7S RNA and at least six polypeptide subunits (relative molecular masses 9, 14, 19, 54, 68, and 72K).
Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Complexes of RNA-binding proteins with ribonucleic acids (RNA).
Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.
A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).
RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.
Peptide initiation factors from eukaryotic organisms. Over twelve factors are involved in PEPTIDE CHAIN INITIATION, TRANSLATIONAL in eukaryotic cells. Many of these factors play a role in controlling the rate of MRNA TRANSLATION.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Peptide elongation factor 1 is a multisubunit protein that is responsible for the GTP-dependent binding of aminoacyl-tRNAs to eukaryotic ribosomes. The alpha subunit (EF-1alpha) binds aminoacyl-tRNA and transfers it to the ribosome in a process linked to GTP hydrolysis. The beta and delta subunits (EF-1beta, EF-1delta) are involved in exchanging GDP for GTP. The gamma subunit (EF-1gamma) is a structural component.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
The small subunit of archaeal RIBOSOMES. It is composed of the 16S RIBOSOMAL RNA and about 28 different RIBOSOMAL PROTEINS.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Sequences within RNA that regulate the processing, stability (RNA STABILITY) or translation (TRANSLATION, GENETIC) of RNA.
Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Peptide initiation factors from prokaryotic organisms. Only three factors are needed for translation initiation in prokaryotic organisms, which occurs by a far simpler process than in PEPTIDE CHAIN INITIATION, TRANSLATIONAL of eukaryotic organisms.
Substances that reduce the growth or reproduction of BACTERIA.
The meaning ascribed to the BASE SEQUENCE with respect to how it is translated into AMINO ACID SEQUENCE. The start, stop, and order of amino acids of a protein is specified by consecutive triplets of nucleotides called codons (CODON).
A family of enzymes that catalyze the endonucleolytic cleavage of RNA. It includes EC 3.1.26.-, EC 3.1.27.-, EC 3.1.30.-, and EC 3.1.31.-.
The largest of the three prokaryotic initiation factors with a molecular size of approximately 80 kD. It functions in the transcription initiation process by promoting the binding of formylmethionine-tRNA to the P-site of the 30S ribosome and by preventing the incorrect binding of elongator tRNA to the translation initiation site.
The sum of the weight of all the atoms in a molecule.
A group of ribonucleotides (up to 12) in which the phosphate residues of each ribonucleotide act as bridges in forming diester linkages between the ribose moieties.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)
The process of cleaving a chemical compound by the addition of a molecule of water.
Proteins found in any species of fungus.
A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Constituent of the 50S subunit of prokaryotic ribosomes containing about 120 nucleotides and 34 proteins. It is also a constituent of the 60S subunit of eukaryotic ribosomes. 5S rRNA is involved in initiation of polypeptide synthesis.
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).

Structural and functional changes in acute liver injury. (1/8245)

Carbon tetrachloride produces liver cell injury in a variety of animal species. The first structurally recognizable changes occur in the endoplasmic reticulum, with alteration in ribosome-membrane interactions. Later there is an increase in intracellular fat, and the formation of tangled nets of the ergastoplasm. At no time are there changes in mitochondria or single membrane limited bodies in cells with intact plasmalemma, although a relative increase in cell sap may appear. In dead cells (those with plasmalemma discontinuties) crystalline deposits of calcium phosphatase may be noted. Functional changes are related to the endoplasmic reticulum and the plasma membrane. An early decrease in protein synthesis takes place; an accumulation of neutral lipid is related to this change. Later alterations in the ergastoplasmic functions (e.g., mixed function oxidation) occurs. Carbon tetrachloride is not the active agent; rather, a product of its metabolism, probably the CC1, free radical, is. The mechanisms of injury include macromolecular adduction and peroxide propagation. A third possibility includes a cascade effect with the production of secondary and tertiary products, also toxic in nature, with the ability to produce more widespread damage to intracellular structures.  (+info)

NMD3 encodes an essential cytoplasmic protein required for stable 60S ribosomal subunits in Saccharomyces cerevisiae. (2/8245)

A mutation in NMD3 was found to be lethal in the absence of XRN1, which encodes the major cytoplasmic exoribonuclease responsible for mRNA turnover. Molecular genetic analysis of NMD3 revealed that it is an essential gene required for stable 60S ribosomal subunits. Cells bearing a temperature-sensitive allele of NMD3 had decreased levels of 60S subunits at the nonpermissive temperature which resulted in the formation of half-mer polysomes. Pulse-chase analysis of rRNA biogenesis indicated that 25S rRNA was made and processed with kinetics similar to wild-type kinetics. However, the mature RNA was rapidly degraded, with a half-life of 4 min. Nmd3p fractionated as a cytoplasmic protein and sedimented in the position of free 60S subunits in sucrose gradients. These results suggest that Nmd3p is a cytoplasmic factor required for a late cytoplasmic assembly step of the 60S subunit but is not a ribosomal protein. Putative orthologs of Nmd3p exist in Drosophila, in nematodes, and in archaebacteria but not in eubacteria. The Nmd3 protein sequence does not contain readily recognizable motifs of known function. However, these proteins all have an amino-terminal domain containing four repeats of Cx2C, reminiscent of zinc-binding proteins, implicated in nucleic acid binding or protein oligomerization.  (+info)

Single atom modification (O-->S) of tRNA confers ribosome binding. (3/8245)

Escherichia coli tRNALysSUU, as well as human tRNALys3SUU, has 2-thiouridine derivatives at wobble position 34 (s2U*34). Unlike the native tRNALysSUU, the full-length, unmodified transcript of human tRNALys3UUU and the unmodified tRNALys3UUU anticodon stem/loop (ASLLys3UUU) did not bind AAA- or AAG-programmed ribosomes. In contrast, the completely unmodified yeast tRNAPhe anticodon stem/loop (ASLPheGAA) had an affinity (Kd = 136+/-49 nM) similar to that of native yeast tRNAPheGmAA (Kd = 103+/-19 nM). We have found that the single, site-specific substitution of s2U34 for U34 to produce the modified ASLLysSUU was sufficient to restore ribosomal binding. The modified ASLLysSUU bound the ribosome with an affinity (Kd = 176+/-62 nM) comparable to that of native tRNALysSUU (Kd = 70+/-7 nM). Furthermore, in binding to the ribosome, the modified ASLLys3SUU produced the same 16S P-site tRNA footprint as did native E. coli tRNALysSUU, yeast tRNAPheGmAA, and the unmodified ASLPheGAA. The unmodified ASLLys3UUU had no footprint at all. Investigations of thermal stability and structure monitored by UV spectroscopy and NMR showed that the dynamic conformation of the loop of modified ASLLys3SUU was different from that of the unmodified ASLLysUUU, whereas the stems were isomorphous. Based on these and other data, we conclude that s2U34 in tRNALysSUU and in other s2U34-containing tRNAs is critical for generating an anticodon conformation that leads to effective codon interaction in all organisms. This is the first example of a single atom substitution (U34-->s2U34) that confers the property of ribosomal binding on an otherwise inactive tRNA.  (+info)

Studies on a nonpolysomal ribonucleoprotein coding for myosin heavy chains from chick embryonic muscles. (4/8245)

A messenger ribonucleoprotein (mRNP) particle containing the mRNA coding for the myosin heavy chain (MHC mRNA) has been isolated from the postpolysomal fraction of homogenates of 14-day-old chick embryonic muscles. The mRNP sediments in sucrose gradient as 120 S and has a characteristic buoyant density of 1.415 g/cm3, which corresponds to an RNA:protein ratio of 1:3.8. The RNA isolated from the 120 S particle behaved like authentic MHC mRNA purified from chick embryonic muscles with respect to electrophoretic mobility and ability to program the synthesis of myosin heavy chain in a rabbit reticulocyte lysate system as judged by multi-step co-purification of the in vitro products with chick embryonic leg muscle myosin added as carrier. The RNA obtained from the 120 S particle was as effective as purified MHC mRNA in stimulating the synthesis of the complete myosin heavy chains in rabbit reticulocyte lysate under conditions where non-muscle mRNAs had no such effect. Analysis of the protein moieties of the 120 S particle by sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows the presence of seven distinct polypeptides with apparent molecular weights of 44,000, 49,000, 53,000, 81,000, 83,000, and 98,000, whereas typical ribosomal proteins are absent. These results indicate that the 120 S particles are distinct cellular entities unrelated to ribosomes or initiation complexes. The presence of muscle-specific mRNAs as cytoplasmic mRNPs suggests that these particles may be involved in translational control during myogenesis in embryonic muscles.  (+info)

Purification and characterization of initiation factor IF-E2 from rabbit reticulocytes. (5/8245)

Initiation factor IF-E2 was isolated from rabbit reticulocytes and purified 120-fold to near homogeneity by ammonium sulfate fractionation, column chromatography on DEAE-cellulose and phosphocellulose, and, when suitable, by sucrose density gradient centrifugation. The factor is a complex protein containing three nonidentical polypeptides of molecular weight 57,000, 52,000, and 36,000. It behaves as a complex throughout its purification and during polyacrylamide gel electrophoresis in nondenaturing buffer but its thress components are readily separated by electrophoresis in denaturing buffers. None of its components corresponds to any of the polypeptides of the other initiation factors or to any proteins of ribosomes washed in buffers containing a high salf concentration. A stoichiometric ratio of 1:1:1 was determined for the three polypeptides; based on the assumption of one copy each per complex, the calculated factor molecular weight is 145,000, a value in agreement with the measured value of 160,000. Initiation factor IF-E2 was radioactively labeled in vitro by reductive alkylation or by phosphorylation with a protein kinase also isolated from rabbit reticulocytes. Neither procedure causes a measurable change in the ability of the factor to form a ternary complex with GTP and the initiator methionyl-tRNA. 5'-Guanylyl-methylenediphosphonate may substitute for GTP, but only at relatively high concentrations. The binding of labeled initiation factor IF-E2 and methionyl-tRNA to the 40 S ribosomal subunit was studied by sucrose density gradient centrifugation. Appreciable binding of the factor is seen only when all three components of the ternary complex are included in the reaction mixture. The binding of either the factor or methionyl-tRNA was not stimulated by the addition of globin messenger RNA and initiation factor IF-E3. It was shown that all three polypeptide components of initiation factor IF-E2 are bound to these nascent initiation complexes.  (+info)

Structure and functions of nucleolin. (6/8245)

Nucleolin is an abundant protein of the nucleolus. Nucleolar proteins structurally related to nucleolin are found in organisms ranging from yeast to plants and mammals. The association of several structural domains in nucleolin allows the interaction of nucleolin with different proteins and RNA sequences. Nucleolin has been implicated in chromatin structure, rDNA transcription, rRNA maturation, ribosome assembly and nucleo-cytoplasmic transport. Studies of nucleolin over the last 25 years have revealed a fascinating role for nucleolin in ribosome biogenesis. The involvement of nucleolin at multiple steps of this biosynthetic pathway suggests that it could play a key role in this highly integrated process.  (+info)

Use of an internal ribosome entry site for bicistronic expression of Cre recombinase or rtTA transactivator. (7/8245)

Conditional gene targeting depends on tissue and time specificity of recombination events. Endogenous promoters are often used to drive various transgenic constructs. To avoid the problems associated with reconstituting a specific expression pattern in transgenic animals by this method, we tested the internal ribosome entry site of the encephalomyocarditis virus, to enable linkage of the Cre recombinase or rtTA trans-activator to 3' untranslated ends of endogenous genes. Here we report that these constructs function effectively in COS cells. The data suggest that these cassettes will be appropriate for 3' targeting of mouse genes.  (+info)

Comparison of synonymous codon distribution patterns of bacteriophage and host genomes. (8/8245)

Synonymous codon usage patterns of bacteriophage and host genomes were compared. Two indexes, G + C base composition of a gene (fgc) and fraction of translationally optimal codons of the gene (fop), were used in the comparison. Synonymous codon usage data of all the coding sequences on a genome are represented as a cloud of points in the plane of fop vs. fgc. The Escherichia coli coding sequences appear to exhibit two phases, "rising" and "flat" phases. Genes that are essential for survival and are thought to be native are located in the flat phase, while foreign-type genes from prophages and transposons are found in the rising phase with a slope of nearly unity in the fgc vs. fop plot. Synonymous codon distribution patterns of genes from temperate phages P4, P2, N15 and lambda are similar to the pattern of E. coli rising phase genes. In contrast, genes from the virulent phage T7 or T4, for which a phage-encoded DNA polymerase is identified, fall in a linear curve with a slope of nearly zero in the fop vs. fgc plane. These results may suggest that the G + C contents for T7, T4 and E. coli flat phase genes are subject to the directional mutation pressure and are determined by the DNA polymerase used in the replication. There is significant variation in the fop values of the phage genes, suggesting an adjustment to gene expression level. Similar analyses of codon distribution patterns were carried out for Haemophilus influenzae, Bacillus subtilis, Mycobacterium tuberculosis and their phages with complete genomic sequences available.  (+info)

Lab computer simulates ribosome in motion Role of the Ribosome, Gwen V. Childs, copied here Ribosome in Proteopedia-The free, ... Archaeal ribosomes share the same general dimensions of bacteria ones, being a 70S ribosome made up from a 50S large subunit, a ... A ribosome is made from complexes of RNAs and proteins and is therefore a ribonucleoprotein complex. Each ribosome is composed ... When a ribosome begins to synthesize proteins that are needed in some organelles, the ribosome making this protein can become " ...
... mitochondrial ribosomes are descended from bacterial ribosomes. However, there has been significant divergence between the two ... The mitochondrial ribosome, or mitoribosome, is a protein complex that is active in mitochondria and functions as a riboprotein ... Mitoribosomes, like cytoplasmic ribosomes, consist of two subunits - large (mtLSU) and small (mt-SSU). Mitoribosomes consist of ... Greber BJ, Bieri P, Leibundgut M, Leitner A, Aebersold R, Boehringer D, Ban N (April 2015). "Ribosome. The complete structure ...
The eukaryotic ribosome, also called the 80S ribosome, is made up of two subunits - the large 60S subunit (which contains the ... The 40S pre-ribosome is transported out of the nucleolus and into the cytoplasm. The cytoplasmic 40S pre-ribosome now contains ... Ribosome biogenesis is the process of making ribosomes. In prokaryotes, this process takes place in the cytoplasm with the ... Because ribosomes are so complex, a certain number of ribosomes are assembled incorrectly and could potentially waste cellular ...
... the distribution of ribosomes on a messenger RNA, and the speed of translating ribosomes. Ribosome profiling targets only mRNA ... Ribosome profiling is based on the discovery that the mRNA within a ribosome can be isolated through the use of nucleases that ... Ribosome profiling, or Ribo-Seq (also named ribosome footprinting), is an adaptation of a technique developed by Joan Steitz ... Using ribonucleases, digest the RNA not protected by ribosomes. Isolate the mRNA-ribosome complexes using sucrose gradient ...
... and thus allows the protein of interest to protrude out of the ribosome and fold. What results is a complex of mRNA, ribosome, ... Ribosome display is a technique used to perform in vitro protein evolution to create proteins that can bind to a desired ligand ... Ribosome display begins with a native library of DNA sequences coding for polypeptides. Each sequence is transcribed, and then ... By having the protein progenitor attached to the complex, the processes of ribosome display skips the microarray/peptide bead/ ...
"80S Ribosomes, Eukaryotic Ribosomes, Prokaryotic Ribosomes, Nucleic Acids, Sedimentation Coefficient". www. ... ribosomes and subject to more complex regulation and biogenesis pathways.Eukaryotic ribosomes are also known as 80S ribosomes, ... Ribosomes from all organisms share a highly conserved catalytic center. However, the ribosomes of eukaryotes (animals, plants, ... "Difference Between 70S Ribosomes and 80S Ribosomes, RNA, Micromolecules". www.microbiologyprocedure.com. Archived from the ...
Synthetic ribosomes are artificial small-molecules that can synthesize peptides in a sequence-specific matter. David Alan ... The Cédric Orelle research group created ribosomes with tethered and inseparable subunits (or Ribo-T). Sleator, RD (2013). " ... "Synthetic ribosomes". Bioengineered. 4 (2): 63-4. doi:10.4161/bioe.23640. PMC 3609622. PMID 23324614. Lewandowski, B; De Bo, G ... "Protein synthesis by ribosomes with tethered subunits". Nature. 524 (7563): 119-124. doi:10.1038/nature14862. PMID 26222032. ( ...
... is a mechanism of translation initiation in which ribosomes bypass, or "shunt over", parts of the 5' ... Ribosome shunting model indicates with the collaboration of initiation factors, ribosomes start scanning from capped 5'-end and ... The mechanism of ribosome shunting in RTBV resembles that in CaMV: it also requires the first short ORF as well as a following ... The mechanism for ribosome shunt involves the larger subunit binding upstream of the start codon. The polymerase is then able ...
A ribosome-inactivating protein (RIP) is a protein synthesis inhibitor that acts at the eukaryotic ribosome. This protein ... Ribosome-inactivating proteins (RIPs) are separated into the following types based on protein domain composition: Type I (A): ... Ribosome+Inactivating+Proteins at the US National Library of Medicine Medical Subject Headings (MeSH) Endo Y, Tsurugi K, ... May MJ, Hartley MR, Roberts LM, Krieg PA, Osborn RW, Lord JM (January 1989). "Ribosome inactivation by ricin A chain: a ...
Since the Kozak sequence itself is not involved in the recruitment of the ribosome, it is not considered a ribosome binding ... the rate at which a ribosome is recruited to the RBS the rate at which a recruited ribosome is able to initiate translation (i. ... Sequences within ribosome binding site affecting messenger RNA translatability and method to direct ribosomes to single ... A ribosome binding site, or ribosomal binding site (RBS), is a sequence of nucleotides upstream of the start codon of an mRNA ...
... or ribosome release factor (RRF) is a protein found in bacterial cells as well as eukaryotic ... Despite the tRNA-mimicry, RRF binds to ribosomes quite differently from the way tRNA does. It has been suggested that ribosomes ... RRF accomplishes the recycling of ribosomes by splitting ribosomes into subunits, thereby releasing the bound mRNA. This also ... Janosi L, Shimizu I, Kaji A (May 1994). "Ribosome recycling factor (ribosome releasing factor) is essential for bacterial ...
Ribosome binding site Ribosome shunting Pelletier J, Sonenberg N (July 1988). "Internal initiation of translation of eukaryotic ... An internal ribosome entry site, abbreviated IRES, is an RNA element that allows for translation initiation in a cap- ... They are described as distinct regions of RNA molecules that are able to recruit the eukaryotic ribosome to the mRNA. This ... Internal ribosome entry site, Cell biology, Nucleotides, Gene expression, Protein biosynthesis, Cis-regulatory RNA elements). ...
... (RNC) refers to the collection of molecules that constitute a ribosome attached to the ... Cabrita LD, Dobson CM, Christodoulou J (February 2010). "Protein folding on the ribosome". Current Opinion in Structural ... Schaffitzel C, Ban N (June 2007). "Generation of ribosome nascent chain complexes for structural and functional studies". ... folding and interactions of both the ribosome and proteins undergoing synthesis. ...
The alpha operon ribosome binding site in bacteria is surrounded by this complex pseudoknotted RNA structure. Translation of ... Page for Alpha operon ribosome binding site at Rfam v t e (Cis-regulatory RNA elements, All stub articles, Molecular and ... The mechanism of repression is thought to involve a conformational switch in the pseudoknot region and ribosome entrapment. ...
ArfA - Alternative ribosome-rescue factor A "Peptidyl-tRNA hydrolase, ribosome rescue factor". BioCyc. SRI International. Chan ... August 2020). "Mechanism of ribosome rescue by alternative ribosome-rescue factor B". Nature Communications. 11 (1): 4106. doi: ... Alternative ribosome-rescue factor B (ArfB, YaeJ) also known as peptidyl-tRNA hydrolase, is a protein that plays a role in ... Feaga HA, Quickel MD, Hankey-Giblin PA, Keiler KC (March 2016). "Human Cells Require Non-stop Ribosome Rescue Activity in ...
The Cripavirus internal ribosome entry site (CrPV IRES) is an RNA element required for the production of capsid proteins ... Page for Cripavirus internal ribosome entry site (IRES) at Rfam v t e (GO template errors, Cis-regulatory RNA elements, ... through ribosome recruitment to an intergenic region IRES (IGR IRES). Cricket paralysis virus Internal ribosome entry site ( ... IRES) Kanamori Y, Nakashima N (February 2001). "A tertiary structure model of the internal ribosome entry site (IRES) for ...
ArfB - Alternative ribosome-rescue factor B Abo T, Chadani Y (2014). "The fail-safe system to rescue the stalled ribosomes in ... Alternative ribosome-rescue factor A (ArfA, YhdL) also known as peptidyl-tRNA hydrolase, is a protein that plays a role in ... Buskirk AR, Green R (March 2017). "Ribosome pausing, arrest and rescue in bacteria and eukaryotes". Philosophical Transactions ... rescuing of stalled ribosomes. It recruits RF2. ...
... (BRIX1) also known as brix domain-containing protein 2 (BXDC2) is a protein that in ...
... is a protein that in humans is encoded by the RSL24D1 gene. This gene encodes a ...
The APC internal ribosome entry site (IRES) is an RNA element which is located in the coding sequence of the APC gene. APC is a ... Page for APC internal ribosome entry site (IRES) at Rfam v t e (Articles with short description, Short description matches ...
Page for Aphthovirus internal ribosome entry site (IRES) at Rfam v t e (GO template errors, Cis-regulatory RNA elements, ... This family represents the internal ribosome entry site (IRES) of the Picornaviruses. IRES elements allow cap and end- ... Internal ribosome entry site, Aphthoviruses, All stub articles, Molecular and cellular biology stubs). ...
Page for Pestivirus internal ribosome entry site (IRES) at Rfam v t e (GO template errors, Cis-regulatory RNA elements, ... This family represents the internal ribosome entry site (IRES) of the pestiviruses. The pestivirus IRES allows cap and end- ... Internal ribosome entry site, All stub articles, Molecular and cellular biology stubs). ...
Ure2 Internal ribosome entry site Nrf2 internal ribosome entry site (IRES) Komar, AA; Lesnik, T; Cullin, C; Merrick, WC; ... In molecular biology, the Ure2 internal ribosome entry site (IRES) is an RNA element present in the 5' UTR of the mRNA of Ure2 ... "A small stem loop element directs internal initiation of the URE2 internal ribosome entry site in Saccharomyces cerevisiae". ...
The Tobamovirus internal ribosome entry site (IRES) is an element that allows cap and end-independent translation of mRNA in ... Page for Tobamovirus internal ribosome entry site (IRES) at Rfam v t e (GO template errors, Cis-regulatory RNA elements, ... "A tobamovirus genome that contains an internal ribosome entry site functional in vitro". Virology. 232 (1): 32-43. doi:10.1006/ ...
Nrf2 Internal ribosome entry site Ure2 internal ribosome entry site (IRES) Li, W; Thakor, N; Xu, EY; Huang, Y; Chen, C; Yu, R; ... It contains a stem-loop structure upstream of a ribosome binding site. This stem loop inhibits ribosome binding and translation ... In molecular biology, the Nrf2 internal ribosome entry site (IRES) is an RNA element present in the 5′ UTR of the mRNA encoding ...
Ray PS, Das S (October 2002). "La autoantigen is required for the internal ribosome entry site-mediated translation of ... This family represents the Picornavirus internal ribosome entry site (IRES) element present in their 5' untranslated region. ... http://rfam.xfam.org/family/RF00229 Picornavirus internal ribosome entry site (IRES) Page for Picornavirus internal ribosome ... entry site (IRES) at Rfam v t e (GO template errors, Cis-regulatory RNA elements, Internal ribosome entry site, Picornaviridae ...
The BiP internal ribosome entry site (IRES) is an RNA element present in the 5' UTR of the mRNA of BiP protein and allows cap- ... Page for bip internal ribosome entry site (IRES) at Rfam v t e (GO template errors, Cis-regulatory RNA elements, All stub ... BiP protein expression has been found to be significantly enhanced by the heat shock response due to internal ribosome entry ...
In molecular biology, the ODC internal ribosome entry site (IRES) is an RNA element present in the 5′ UTR of the mRNA encoding ... Ornithine decarboxylase Internal ribosome entry site Pyronnet, S; Pradayrol, L; Sonenberg, N (April 2000). "A cell cycle- ... Pyronnet, S; Pradayrol, L; Sonenberg, N (June 2005). "Alternative splicing facilitates internal ribosome entry on the ornithine ... dependent internal ribosome entry site". Molecular Cell. 5 (4): 607-616. doi:10.1016/s1097-2765(00)80240-3. PMID 10882097. ...
Page for Bag-1 internal ribosome entry site (IRES) at Rfam v t e (GO template errors, Cis-regulatory RNA elements, All stub ... The bag-1 internal ribosome entry site (IRES) is a cis-acting element located in the 5 ' untranslated region of the BAG-1 ... "The p36 isoform of BAG-1 is translated by internal ribosome entry following heat shock". Oncogene. 20 (30): 4095-4100. doi: ...
The FGF-2 internal ribosome entry site is an RNA element present in the 5' UTR of the mRNA of fibroblast growth factor-2. It ... Page for FGF-2 internal ribosome entry site (IRES) at Rfam v t e (GO template errors, Cis-regulatory RNA elements, All stub ... "Fibroblast growth factor 2 internal ribosome entry site (IRES) activity ex vivo and in transgenic mice reveals a stringent ... "Alternative translation of human fibroblast growth factor 2 mRNA occurs by internal entry of ribosomes". Molecular and Cellular ...
EMPIAR, the Electron Microscopy Public Image Archive centered at EMBL-EBI, is a public resource for raw electron microscopy images related to EMDB, contains micrographs, particle sets and tilt-series.
Cells have perfected action at a distance: not by magic, but by control of distant sites through carefully arranged functional intermediates.. ...
3D structure of the ribosome. This cryo-electron microscopy image shows the 3D structure of the ribosome (yellow/blue) bound to ...
Ribosomes arranged in pairs (100S) have been related with nutritional stress response and are believed to represent a " ... In situ studies with intact E. coli cells allowed us to demonstrate that 100S ribosomes do exist in vivo and represent an ... Structure of hibernating ribosomes studied by cryoelectron tomography in vitro and in situ. ... We have used cryoelectron tomography to reveal the three-dimensional configuration of 100S ribosomes isolated from starved ...
During this process, a portion of the ribosomes ... Attachment of ribosomes to the outer membrane of isolated ... ATTACHMENT OF RIBOSOMES TO MEMBRANES DURING POLYSOME FORMATION IN MOUSE SARCOMA 180 CELLS Se Yong Lee, Se Yong Lee ... During this process, a portion of the ribosomes originally found in the 17,000 g (10 min centrifugation) supernatant of cell ... Se Yong Lee, Velibor Krsmanovic, George Brawerman; ATTACHMENT OF RIBOSOMES TO MEMBRANES DURING POLYSOME FORMATION IN MOUSE ...
Filed Under: awards, Biochemistry, Biology, events Tagged With: Drosophila, initiation factors, IRES, Marr lab, ribosomes, ... You are here: Home / Archives for ribosomes. 2012 Rosenstiel Award Recipient, Dr. Nahum Sonenberg. January 2, 2012 By Calla ... In this way, viral mRNAs are able to outcompete eukaryotic mRNAs for ribosome binding and in many cases become the most ... that the uncapped viral mRNA from poliovirus recruits the ribosome to internal regions of the 5 untranslated region (UTR). ...
Free ribosomes synthesize proteins in the cytoplasm.. *Membrane-bound Ribosomes: Most of the ribosomes in a cell are placed on ... Prokaryotes have 70S ribosomes and eukaryotes have 80S ribosomes.. Question 3: What is the chemical composition of a ribosome? ... Ribosomes are of two kinds, cytoplasmic and organelle. The organelle ribosomes are found in plastids (plastid ribosomes) and ... Hereunder is a detailed explanation of Ribosomes and inclusion bodies.. Ribosomes. Ribosomes are naked ribonucleoprotein ...
Conditions Connected With Ribosomes. par linxeo , Jan 23, 2018 , uncategorized , 0 commentaires ...
The nucleolus is the site of synthesis of the ribosomes inside the cell. The nucleolus is usually found as a dark spot inside ... Synthesis and secretion of enzymes and hormonesRibosomes(iv)____(v)____ Intracellular digestion. ... It is responsible for a lot of enzymatic activities, but not the synthesis of ribosomes. ...
Crystallization and Preliminary X-Ray Diffraction Analysis of PD-L4, a Ribosome Inactivating Protein from Phytolacca dioica L. ... Crystallization and Preliminary X-Ray Diffraction Analysis of PD-L4, a Ribosome Inactivating Protein from Phytolacca dioica L. ...
In liver, one milliliter contains 2 × 10 ribosomes.. Size of Ribosomes:. There are mainly two sizes of ribosomes - (i) One is ... Ribosomes are also found in mitochondria and chloroplasts. These ribosomes are always smaller than 80S cytoplasmic ribosomes. ... In liver cell 75% ribosomes are membrane bound and remaining 25% present free in cytoplasm. Membrane bound ribosomes are ... Ribosomes were first isolated from E. coli by Tissieres and J. D. Watson (1958), who found that ribosomal RNA alone accounts ...
The Resource Ribosome Inactivating Toxins Label Ribosome Inactivating Toxins. Statement of responsibility Daniel Gillet. ... Ribosome Inactivating Toxins Resource Information The work Ribosome Inactivating Toxins represents a distinct intellectual or ... Data Citation of the Work Ribosome Inactivating Toxins. Copy and paste the following RDF/HTML data fragment to cite this ... Ribosome Inactivating Toxins,/a,,/span, - ,span property=potentialAction typeOf=OrganizeAction,,span property=agent ...
Eukaryotic ribosomes are significantly larger than prokaryotic ribosomes in part because of their ESs. To determine ES ... Numerous regions within the ribosome, including ESs, remain un-explored as drug targets. ESs were screened for selective small ... Eukaryotic ribosomes are significantly larger than prokaryotic ribosomes in part because of their ESs. To determine ES ... Numerous regions within the ribosome, including ESs, remain un-explored as drug targets. ESs were screened for selective small ...
Structure of the ribosome with elongation factor G trapped in the pretranslocation state ... coli EF-F-ribosome preparation [1]. The data was collected at 300 kV on an FEI Titan Krios microscope and Falcon I direct ...
Quality control ensures fidelity in ribosome assembly and cellular health. Quality control ensures fidelity in ribosome ... In this review, we outline our understanding of quality control within ribosome synthesis and how failure to enforce quality ... Quality control is critical in maintaining the integrity of ribosomes and necessary to support healthy cell growth and prevent ... Its importance is demonstrated by the finding that bypassing quality control leads to misassembled, malfunctioning ribosomes ...
Multiple roles of the general regulatory factor Abf1 in yeast ribosome biogenesis *Beatrice Fermi ...
Here we show that Eri1 associates with ribosomes and ribosomal RNA (rRNA). Ribosomes from Eri1-deficient mice contain 5.8S rRNA ... Mouse Eri1 interacts with the ribosome and catalyzes 5.8S rRNA processing. ... Ribosomes. Life Sciences. Medicine and Health Sciences ...
Late-stage 40S ribosome assembly is a highly regulated dynamic process that occurs in the cytoplasm, alongside the full ... 2017) Structural Heterogeneity in Pre-40S Ribosomes. Structure 25(2):329-340. ...
Ribosomes slide on lysine-encoding homopolymeric A stretches. Kristin S. Koutmou, Anthony P. Schuller, Julie L. Brunelle, ... Dive into the research topics of Ribosomes slide on lysine-encoding homopolymeric A stretches. Together they form a unique ...
Temperature-dependent radiation sensitivity and order of 70S ribosome crystals journal, October 2014 * Warkentin, Matthew; ... As a test case, the radiation sensitivity of 70S ribosome crystals has been examined. At T = 100 and 300 K, the half doses are ... 70S ribosome crystals exhibit substantially increased resolution at 100 K relative to 300 K owing to cooling-induced ordering ... Temperature-dependent radiation sensitivity and order of 70S ribosome crystals. Journal Article Warkentin, Matthew ; Hopkins, ...
ribosome. a structure composed of RNA and protein that constructs proteins based on the instructions provided by DNA; may be ... a network of membranes that helps process molecules in a cell and transports cell materials; may be rough (with ribosomes ...
Ribosome Binding Site Characterization. A ribosomal binding site sequence is a specific mRNA sequence that folds in such a way ... This ribosome binds to the mRNA molecule and starts translation of the mRNA into protein. ... A perfect way to implement this variation in the alkane degradation pathway is by using ribosome binding sites with varying ... This led to the characterization of the ribosome initiation strengths of five Anderson RBS family members. ...
Ribosome is essential for all forms of life. ... Ribosome is essential for all forms of life. Ribosome ... Sanjaya Abeysirigunawardena Chemistry & Biochemistry , Post-transcriptional RNA modification and Ribosome assembly ... that bind to bacterial ribosomes during ribosome biogenesis. Our laboratory has developed several fluorescence- and gel-based ... Similarly, bacterial ribosomes reconstituted with in vitro transcribed 23S rRNAs that the lack of nucleotide modifications show ...
In addition, the use in the test of an excess of cspA mRNA over the ribosomes should have minimized any possible influence of ... and (2) an increased number of ribosomes translating cspA mRNA at low temperature, leading to the protection of the transcript ... the secondary structure of these mRNAs, which below a certain temperature occludes access to the ribosome, is melted by ... This different folding of the 5′UTR as a function of temperature produces significant structural changes of the ribosome ...
Identifying Ribosome Pause Sites FINAL.pdf Item Details. abstract. Ribosome frameshifting, pausing, and termination events have ... A combination of techniques for ribosome-protected mRNA fragment isolation (ribosome footprinting) and high-throughput ... Ribosomes High-throughput Sequencing contributor. Bender, R. Hugh F. (author) Tague, Brian (committee chair) Curran, James ( ... We suggest that these mechanisms may be studied on a global scale by mapping the distribution of ribosomes along a select group ...
Solution structure of a putative ribosome-binding factor from Mycoplasma pneumoniae (MPN156) ... Solution structure of a putative ribosome-binding factor from Mycoplasma pneumoniae (MPN156) Coordinates. PDB Format Method. ... Rubin, S.M. et al., Solution structure of a putative ribosome binding protein from Mycoplasma pneumoniae and comparison to a ...
internal electron-dense granules resembling ribosomes Site of Virion Assembly. Site of Virion Accumulation. ...
RER and clusters of ribosomes. Paniz-Mondolfi et al. (16). Brain. Vacuole containing circular particles (3, A, B). ...
Abrin; conotoxins; diacetoxyscirpenol; ricin; saxitoxin; Shiga-like ribosome inactivating proteins; tetrodotoxin Exclusions: ¶ ... 100 mg of Shiga-like ribosome inactivating proteins; or 100 mg of tetrodotoxin ...
  • In 1988, the Sonenberg lab made the groundbreaking discovery (Nature 1988, http://www.ncbi.nlm.nih.gov/pubmed/2839775 ) that the uncapped viral mRNA from poliovirus recruits the ribosome to internal regions of the 5' untranslated region (UTR). (brandeis.edu)
  • The different ribosomes of a polyribosome are connected with an mRNA strand. (geeksforgeeks.org)
  • A ribosomal binding site sequence is a specific mRNA sequence that folds in such a way that it attracts the ribosome. (igem.org)
  • This ribosome binds to the mRNA molecule and starts translation of the mRNA into protein. (igem.org)
  • So the encoded mRNA is then read by the ribosome. (cdc.gov)
  • At the ribosome, the processed mRNA is translated to produce proteins from amino acid units. (cdc.gov)
  • mRNA contains the chemical instructions that ribosomes, the protein-making machinery in cells, use to make proteins. (cdc.gov)
  • Using the genetic code of the SARS-CoV-2 virus, vaccine manufacturers developed mRNA that instructs ribosomes to produce the spike protein of the SARS-CoV-2 virus. (cdc.gov)
  • Ribosomes were first isolated from E. coli by Tissieres and J. D. Watson (1958), who found that ribosomal RNA alone accounts for 22% of the total weight in rapidly growing cells (90% of total RNA). (yourarticlelibrary.com)
  • Membrane bound ribosomes are attached to the membrane via large ribosomal subunit. (yourarticlelibrary.com)
  • The coordinated integration of ribosomal RNA and protein into two functional ribosomal subunits is safeguarded by quality control checkpoints that ensure ribosomes are correctly assembled and functional before they engage in translation. (bvsalud.org)
  • Here we show that Eri1 associates with ribosomes and ribosomal RNA (rRNA). (umassmed.edu)
  • Ribosome biogenesis is a complex process that requires synchronization of various cellular events including transcription of ribosomal RNA, ribosomal protein binding, RNA processing and the post-transcriptional and -translational modifications of ribosomal RNA and proteins respectively. (kent.edu)
  • 4-5] We are currently investigating the presence of similar binding corporativity between the ribosomal proteins and three RNA modification enzymes (RsuA, RsmG and RsmC) that bind to bacterial ribosomes during ribosome biogenesis. (kent.edu)
  • Abeysirigunawardena, S. C., Woodson, S. A., Differential effects of ribosomal proteins and Mg2+ ions on a conformational switch during 30S ribosome 5'-domain assembly, RNA. (kent.edu)
  • This gene provides instructions for making a protein called ribosomal protein SA, which is a component of ribosomes. (medlineplus.gov)
  • Within the ribosome, the function of the ribosomal protein SA is unclear. (medlineplus.gov)
  • Ribosomes are naked ribonucleoprotein protoplasmic particles (RNP) with a length of 200-340 Å and diameter of 170-240 Å which function as the sites for protein or polypeptide synthesis. (geeksforgeeks.org)
  • Ribosomes are known as protein factories . (geeksforgeeks.org)
  • Its importance is demonstrated by the finding that bypassing quality control leads to misassembled, malfunctioning ribosomes with altered translation fidelity, which change gene expression and disrupt protein homeostasis . (bvsalud.org)
  • 7-8] At the same time, these modifications also can perturb protein binding, and hence influence ribosome biogenesis. (kent.edu)
  • A shortage of the normal protein likely impairs the assembly of ribosomes, but the specific effects of the mutations are not known. (medlineplus.gov)
  • The cytoplasmic ribosomes (mitoribosomes) may remain free in the cytoplasmic matrix or attached to the surface of the endoplasmic reticulum via the larger or 60S subunits. (geeksforgeeks.org)
  • Prokaryotic cells have only free cytoplasmic ribosomes. (geeksforgeeks.org)
  • All three types of ribosomes produce different types of proteins, e.g., structural proteins from free cytoplasmic ribosomes and globular proteins from ribosomes bound to ER. (geeksforgeeks.org)
  • These ribosomes are always smaller than 80S cytoplasmic ribosomes. (yourarticlelibrary.com)
  • In this way, viral mRNAs are able to outcompete eukaryotic mRNAs for ribosome binding and in many cases become the most abundant transcript being translated. (brandeis.edu)
  • Eukaryotic ribosomes are significantly larger than prokaryotic ribosomes in part because of their ESs. (gatech.edu)
  • We have used cryoelectron tomography to reveal the three-dimensional configuration of 100S ribosomes isolated from starved Escherichia coli cells and we have described their mode of interaction. (cipsm.de)
  • Many ribosomes occur in a cell e.g., a single cell of E. coli has 20000-30000 ribosomes. (geeksforgeeks.org)
  • The attached archive contains Frealign parameter files and scripts that were used to calculate 15 classes from 1.3 million single particle images of an E. coli EF-F-ribosome preparation [1] . (umassmed.edu)
  • There are mainly two sizes of ribosomes - (i) One is smaller prokaryotic found in bacteria and blue-green algae, having a sedimentation coefficient 70S equivalent to a molecular weight of 2.7 × 10 6 daltons. (yourarticlelibrary.com)
  • RNase treatment released about 40% of the attached ribosomes as monomers, and ethylenediaminetetraacetic acid released 60% as subunits. (rupress.org)
  • Each ribosome consists of two unequal subunits, larger dome-shaped, and smaller ovoid. (geeksforgeeks.org)
  • The two subunits dissociate below 0.0001 M Mg 2 + while above this strength, the ribosomes can come together to form dimers. (geeksforgeeks.org)
  • Each ribosome has two parts (subunits) called the large and small subunits. (medlineplus.gov)
  • During this process, a portion of the ribosomes originally found in the 17,000 g (10 min centrifugation) supernatant of cell lysates becomes firmly attached to structures sedimenting at 500 g (5 min centrifugation). (rupress.org)
  • Specialized cell structures called ribosomes are the cellular organelles that actually synthesize the proteins (RNA transcription). (cdc.gov)
  • Other shapes within the painting resemble biologic structures, including flagella, ribosomes, and genetic material found in bacteria. (cdc.gov)
  • In eukaryotes, cells engaged in producing proteins for export, such as exocrine pancreas, which synthesize various digestive enzymes or plasma cells which produce immunoglobulins, most ribosomes (90%) are associated with membranes. (yourarticlelibrary.com)
  • Palade (1953) was the first to observe the ribosomes as dense particles or granules in electron microscope. (yourarticlelibrary.com)
  • It is suggested that during polysome formation a portion of the ribosomes becomes attached to the membranes through the intermediary of messenger RNA. (rupress.org)
  • Several proteins have been identified that are associated with 100S ribosomes but their spatial organization has hitherto not been characterized. (cipsm.de)
  • The bound ribosomes generally transfer their proteins to the cisternae of the endoplasmic reticulum for transport to other parts both inside and outside the cell. (geeksforgeeks.org)
  • Research suggests that it helps the ribosome control the production of certain proteins, many of which are likely important for development before birth. (medlineplus.gov)
  • This cryo-electron microscopy image shows the 3D structure of the ribosome (yellow/blue) bound to the signal recognition particle (SRP) and the SRP receptor (both in red). (embl.org)
  • In liver cell 75% ribosomes are membrane bound and remaining 25% present free in cytoplasm. (yourarticlelibrary.com)
  • Ribosomes may occur in spiral or helical groups called polyribosomes or polysomes . (geeksforgeeks.org)
  • Quality control ensures fidelity in ribosome assembly and cellular health. (bvsalud.org)
  • This fraction prepared from recovering cells showed numerous ribosome clusters associated with the ER network. (rupress.org)
  • The nucleolus is the site of synthesis of the ribosomes inside the cell. (byjus.com)
  • It is responsible for a lot of enzymatic activities, but not the synthesis of ribosomes. (byjus.com)
  • In this review , we outline our understanding of quality control within ribosome synthesis and how failure to enforce quality control contributes to human disease . (bvsalud.org)
  • This led to the characterization of the ribosome initiation strengths of five Anderson RBS family members. (igem.org)
  • Similarly, bacterial ribosomes reconstituted with in vitro transcribed 23S rRNAs that the lack of nucleotide modifications show a five-fold reduction in peptidyl-transferase activity. (kent.edu)
  • The organelle ribosomes are found in plastids (plastid ribosomes) and mitochondria (mitoribosomes). (geeksforgeeks.org)
  • Ribosomes are also found in mitochondria and chloroplasts. (yourarticlelibrary.com)
  • Hereunder is a detailed explanation of Ribosomes and inclusion bodies. (geeksforgeeks.org)
  • Quality control is critical in maintaining the integrity of ribosomes and necessary to support healthy cell growth and prevent diseases associated with mistakes in ribosome assembly. (bvsalud.org)
  • We first provide a definition of quality control to guide our investigation, briefly present the main assembly steps, and then examine stages of assembly that test ribosome function, establish a pass-fail system to evaluate these functions, and contribute to altered ribosome performance when bypassed, and are thus considered " quality control . (bvsalud.org)
  • Late-stage 40S ribosome assembly is a highly regulated dynamic process that occurs in the cytoplasm, alongside the full translation machinery. (yeastgenome.org)
  • Ribosomes from Eri1-deficient mice contain 5.8S rRNA that is aberrantly extended at its 3' end, and Eri1, but not a catalytically inactive mutant, converts this abnormal 5.8S rRNA to the wild-type form in vitro and in cells. (umassmed.edu)
  • Ribosomes happen in all living cells with the exception of mammalian erythrocytes. (geeksforgeeks.org)
  • In reticulocytes, embryonic nerve cells and meristematic plant tissues ribosomes are found free. (yourarticlelibrary.com)
  • The work Ribosome Inactivating Toxins represents a distinct intellectual or artistic creation found in Bates College . (bates.edu)
  • Number and concentration of ribosomes are related with RNA content of cell and basophilic properties of cytoplasm. (yourarticlelibrary.com)
  • Numerous regions within the ribosome, including ESs, remain un-explored as drug targets. (gatech.edu)
  • Le fait de nourrir des poulets avec des stéroïdes contraceptifs oraux à la dose utilisée par certains éleveurs de volailles en Egypte a entraîné la formation d'importants résidus d'oestrogènes dans les muscles et le foie par rapport à ceux des poulets témoins. (who.int)
  • In oocytes of lizards, a number of ribosomes become organised into crystalline sheet, which store large number of inactive ribosomes for use during early development. (yourarticlelibrary.com)
  • The size of the ribosomes is determined by the sedimentation coefficient in the centrifuge which is measured as a Svedberg unit called S (S = 1 x 10 - 13 sec). (geeksforgeeks.org)
  • A perfect way to implement this variation in the alkane degradation pathway is by using ribosome binding sites with varying strengths. (igem.org)