Proteins found in any species of archaeon.
Ribonucleic acid in archaea having regulatory and catalytic roles as well as involvement in protein synthesis.
One of the three domains of life (the others being BACTERIA and Eukarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: (1) the presence of characteristic tRNAs and ribosomal RNAs; (2) the absence of peptidoglycan cell walls; (3) the presence of ether-linked lipids built from branched-chain subunits; and (4) their occurrence in unusual habitats. While archaea resemble bacteria in morphology and genomic organization, they resemble eukarya in their method of genomic replication. The domain contains at least four kingdoms: CRENARCHAEOTA; EURYARCHAEOTA; NANOARCHAEOTA; and KORARCHAEOTA.
The small subunit of archaeal RIBOSOMES. It is composed of the 16S RIBOSOMAL RNA and about 28 different RIBOSOMAL PROTEINS.
A family of anaerobic, coccoid to rod-shaped METHANOBACTERIALES. Cell membranes are composed mainly of polyisoprenoid hydrocarbons ether-linked to glycerol. Its organisms are found in anaerobic habitats throughout nature.
Deoxyribonucleic acid that makes up the genetic material of archaea.
The functional genetic units of ARCHAEA.
The genetic complement of an archaeal organism (ARCHAEA) as represented in its DNA.
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.
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.
Viruses whose hosts are in the domain ARCHAEA.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in archaea.
A genus of aerobic, chemolithotrophic, coccoid ARCHAEA whose organisms are thermoacidophilic. Its cells are highly irregular in shape, often lobed, but occasionally spherical. It has worldwide distribution with organisms isolated from hot acidic soils and water. Sulfur is used as an energy source.
An order of anaerobic methanogens in the kingdom EURYARCHAEOTA. They are pseudosarcina, coccoid or sheathed rod-shaped and catabolize methyl groups. The cell wall is composed of protein. The order includes one family, METHANOCOCCACEAE. (From Bergey's Manual of Systemic Bacteriology, 1989)
A kingdom in the domain ARCHAEA comprised of thermoacidophilic, sulfur-dependent organisms. The two orders are SULFOLOBALES and THERMOPROTEALES.
Structures within the nucleus of archaeal cells consisting of or containing DNA, which carry genetic information essential to the cell.
A genus of anaerobic coccoid METHANOCOCCACEAE whose organisms are motile by means of polar tufts of flagella. These methanogens are found in salt marshes, marine and estuarine sediments, and the intestinal tract of animals.
A species of thermoacidophilic ARCHAEA in the family Sulfolobaceae, found in volcanic areas where the temperature is about 80 degrees C and SULFUR is present.
A species of halophilic archaea found in the Dead Sea.
A species of strictly anaerobic, hyperthermophilic archaea which lives in geothermally-heated marine sediments. It exhibits heterotropic growth by fermentation or sulfur respiration.
The large subunit of the archaeal 70s ribosome. It is composed of the 23S RIBOSOMAL RNA, the 5S RIBOSOMAL RNA, and about 40 different RIBOSOMAL PROTEINS.
A species of gram-negative hyperthermophilic ARCHAEA found in deep ocean hydrothermal vents. It is an obligate anaerobe and obligate chemoorganotroph.
The relationships of groups of organisms as reflected by their genetic makeup.
A species of extremely thermophilic, sulfur-reducing archaea. It grows at a maximum temperature of 95 degrees C. in marine or deep-sea geothermal areas.
A genus of anaerobic, irregular spheroid-shaped METHANOSARCINALES whose organisms are nonmotile. Endospores are not formed. These archaea derive energy via formation of methane from acetate, methanol, mono-, di-, and trimethylamine, and possibly, carbon monoxide. Organisms are isolated from freshwater and marine environments.
A species of aerobic, chemolithotrophic ARCHAEA consisting of coccoid cells that utilize sulfur as an energy source. The optimum temperature for growth is 70-75 degrees C. They are isolated from acidic fields.
Anaerobic hyperthermophilic species of ARCHAEA, isolated from hydrothermal fluid samples. It is obligately heterotrophic with coccoid cells that require TRYPTOPHAN for growth.
An RNA-containing enzyme that plays an essential role in tRNA processing by catalyzing the endonucleolytic cleavage of TRANSFER RNA precursors. It removes the extra 5'-nucleotides from tRNA precursors to generate mature tRNA molecules.
RNA that has catalytic activity. The catalytic RNA sequence folds to form a complex surface that can function as an enzyme in reactions with itself and other molecules. It may function even in the absence of protein. There are numerous examples of RNA species that are acted upon by catalytic RNA, however the scope of this enzyme class is not limited to a particular type of substrate.
Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.
A class of enzymes that catalyze the conversion of a nucleotide and water to a nucleoside and orthophosphate. EC 3.1.3.-.
A species of halophilic archaea found in the Mediterranean Sea. It produces bacteriocins active against a range of other halobacteria.
A glycoprotein enzyme present in various organs and in many cells. The enzyme catalyzes the hydrolysis of a 5'-ribonucleotide to a ribonucleoside and orthophosphate in the presence of water. It is cation-dependent and exists in a membrane-bound and soluble form. EC 3.1.3.5.
Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm, and pre-rRNA processing in the nucleolus (see RIBONUCLEOPROTEINS, SMALL NUCLEOLAR).
Databases containing information about PROTEINS such as AMINO ACID SEQUENCE; PROTEIN CONFORMATION; and other properties.
The protein components that constitute the common core of small nuclear ribonucleoprotein particles. These proteins are commonly referred as Sm nuclear antigens due to their antigenic nature.
A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.
The portion of an interactive computer program that issues messages to and receives commands from a user.
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
An enzyme that catalyzes the HYDROLYSIS of the N-glycosidic bond between sugar phosphate backbone and URACIL residue during DNA synthesis.
A family of DNA repair enzymes that recognize damaged nucleotide bases and remove them by hydrolyzing the N-glycosidic bond that attaches them to the sugar backbone of the DNA molecule. The process called BASE EXCISION REPAIR can be completed by a DNA-(APURINIC OR APYRIMIDINIC SITE) LYASE which excises the remaining RIBOSE sugar from the DNA.
A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.
Degree of saltiness, which is largely the OSMOLAR CONCENTRATION of SODIUM CHLORIDE plus any other SALTS present. It is an ecological factor of considerable importance, influencing the types of organisms that live in an ENVIRONMENT.
NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.
Stable nitrogen atoms that have the same atomic number as the element nitrogen, but differ in atomic weight. N-15 is a stable nitrogen isotope.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
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.
Proteins conjugated with deoxyribonucleic acids (DNA) or specific DNA.