A form-genus of unicellular CYANOBACTERIA in the order Chroococcales. None of the strains fix NITROGEN, there are no gas vacuoles, and sheath layers are never produced.

A phylum of oxygenic photosynthetic bacteria comprised of unicellular to multicellular bacteria possessing CHLOROPHYLL a and carrying out oxygenic PHOTOSYNTHESIS. Cyanobacteria are the only known organisms capable of fixing both CARBON DIOXIDE (in the presence of light) and NITROGEN. Cell morphology can include nitrogen-fixing heterocysts and/or resting cells called akinetes. Formerly called blue-green algae, cyanobacteria were traditionally treated as ALGAE.

Light energy harvesting structures attached to the THYLAKOID MEMBRANES of CYANOBACTERIA and RED ALGAE. These multiprotein complexes contain pigments (PHYCOBILIPROTEINS) that transfer light energy to chlorophyll a.

A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.

Proteins found in any species of bacterium.

Protein complexes that take part in the process of PHOTOSYNTHESIS. They are located within the THYLAKOID MEMBRANES of plant CHLOROPLASTS and a variety of structures in more primitive organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.

A large multisubunit protein complex that is found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to drive electron transfer reactions that result in either the reduction of NADP to NADPH or the transport of PROTONS across the membrane.

Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.

The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)

The metal-free blue phycobilin pigment in a conjugated chromoprotein of blue-green algae. It functions as light-absorbing substance together with chlorophylls.

Membranous cisternae of the CHLOROPLAST containing photosynthetic pigments, reaction centers, and the electron-transport chain. Each thylakoid consists of a flattened sac of membrane enclosing a narrow intra-thylakoid space (Lackie and Dow, Dictionary of Cell Biology, 2nd ed). Individual thylakoids are interconnected and tend to stack to form aggregates called grana. They are found in cyanobacteria and all plants.

That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.

Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.

Complexes containing CHLOROPHYLL and other photosensitive molecules. They serve to capture energy in the form of PHOTONS and are generally found as components of the PHOTOSYSTEM I PROTEIN COMPLEX or the PHOTOSYSTEM II PROTEIN COMPLEX.

The functional hereditary units of BACTERIA.

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.

Processes by which phototrophic organisms use sunlight as their primary energy source. Contrasts with chemotrophic processes which do not depend on light and function in deriving energy from exogenous chemical sources. Photoautotrophy (or photolithotrophy) is the ability to use sunlight as energy to fix inorganic nutrients to be used for other organic requirements. Photoautotrophs include all GREEN PLANTS; GREEN ALGAE; CYANOBACTERIA; and green and PURPLE SULFUR BACTERIA. Photoheterotrophs or photoorganotrophs require a supply of organic nutrients for their organic requirements but use sunlight as their primary energy source; examples include certain PURPLE NONSULFUR BACTERIA. Depending on environmental conditions some organisms can switch between different nutritional modes (AUTOTROPHY; HETEROTROPHY; chemotrophy; or phototrophy) to utilize different sources to meet their nutrients and energy requirements.

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.

Polyunsaturated side-chain quinone derivative which is an important link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.

Open chain tetrapyrroles that function as light harvesting chromophores in PHYCOBILIPROTEINS.

A pre-emergent herbicide.

A copper-containing plant protein that is a fundamental link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.

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.

The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)

Any normal or abnormal coloring matter in PLANTS; ANIMALS or micro-organisms.

A form-genus of spherical to rod-shaped CYANOBACTERIA in the order Chroococcales. They contain THYLAKOIDS and are found in a wide range of habitats.

Four PYRROLES joined by one-carbon units linking position 2 of one to position 5 of the next. The conjugated bond system results in PIGMENTATION.

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).

Products of the hydrolysis of chlorophylls in which the phytic acid side chain has been removed and the carboxylic acids saponified.

The metal-free red phycobilin pigment in a conjugated chromoprotein of red algae. It functions as a light-absorbing substance together with chlorophylls.

A protein complex that includes CYTOCHROME B6 and CYTOCHROME F. It is found in the THYLAKOID MEMBRANE and plays an important role in process of PHOTOSYNTHESIS by transferring electrons from PLASTOQUINONE to PLASTOCYANIN or CYTOCHROME C6. The transfer of electrons is coupled to the transport of PROTONS across the membrane.

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

The absence of light.

Cytochromes f are found as components of the CYTOCHROME B6F COMPLEX. They play important role in the transfer of electrons from PHOTOSYSTEM I to PHOTOSYSTEM II.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

A genus of CYANOBACTERIA consisting of trichomes that are untapered with conspicuous constrictions at cross-walls. A firm individual sheath is absent, but a soft covering is often present. Many species are known worldwide as major components of freshwater PLANKTON and also of many saline lakes. The species ANABAENA FLOS-AQUAE is responsible for acute poisonings of various animals.

Light harvesting proteins found in phycobilisomes.

At low concentrations, this compound inhibits reduction of conventional hydrophilic electron acceptors, probably acting as a plastoquinone antagonist. At higher concentrations, it acts as an electron acceptor, intercepting electrons either before or at the site of its inhibitory activity.

Oxidoreductases that specifically reduce arsenate ion to arsenite ion. Reduction of arsenate is a critical step for its biotransformation into a form that can be transported by ARSENITE TRANSPORTING ATPASES or complexed by specific sulfhydryl-containing proteins for the purpose of detoxification (METABOLIC DETOXIFICATION, DRUG). Arsenate reductases require reducing equivalents such as GLUTAREDOXIN or AZURIN.

The processes by which organisms use simple inorganic substances such as gaseous or dissolved carbon dioxide and inorganic nitrogen as nutrient sources. Contrasts with heterotrophic processes which make use of organic materials as the nutrient supply source. Autotrophs can be either chemoautotrophs (or chemolithotrophs), largely ARCHAEA and BACTERIA, which also use simple inorganic substances for their metabolic energy reguirements; or photoautotrophs (or photolithotrophs), such as PLANTS and CYANOBACTERIA, which derive their energy from light. Depending on environmental conditions some organisms can switch between different nutritional modes (autotrophy; HETEROTROPHY; chemotrophy; or PHOTOTROPHY) to utilize different sources to meet their nutrient and energy requirements.

Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.

The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.

An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.

The excision of in-frame internal protein sequences (INTEINS) of a precursor protein, coupled with ligation of the flanking sequences (EXTEINS). Protein splicing is an autocatalytic reaction and results in the production of two proteins from a single primary translation product: the intein and the mature protein.

A class of enzymes that catalyze the cleavage of C-C, C-O, and C-N, and other bonds by other means than by hydrolysis or oxidation. (Enzyme Nomenclature, 1992) EC 4.

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.

A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.

A collective name for a group of closely related lipids that contain substitutions on the 2H-1-benzopyran-6-ol nucleus and a long hydrocarbon chain of isoprenoid units. They are antioxidants by virtue of the phenolic hydrogen. Tocopherols react with the most reactive form of oxygen and protect unsaturated fatty acids from oxidation.

The genetic complement of a BACTERIA as represented in its DNA.

The general name for a group of fat-soluble pigments found in green, yellow, and leafy vegetables, and yellow fruits. They are aliphatic hydrocarbons consisting of a polyisoprene backbone.

An enzyme that catalyzes the conversion of 4-hydroxyphenylpyruvate plus oxygen to homogentisic acid and carbon dioxide. EC 1.13.11.27.

A form-genus of CYANOBACTERIA in the order Nostocales. Trichomes composed of spherical or ovoid vegetative cells along with heterocysts and akinetes. The species form symbiotic associations with a wide range of eukaryotes.

An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.

A blue-green biliprotein widely distributed in the plant kingdom.

Adaptation to a new environment or to a change in the old.

The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.

A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).

Phytol is a diterpene alcohol that is a degradation product of chlorophyll and is used in the synthesis of vitamins E and K and other compounds in animals, but can also act as a phytoestrogen in certain plants.

Glucosides are glycosides that contain glucose as the sugar component, often forming part of the plant's defense mechanism and can have various pharmacological effects when extracted and used medically.

A natural tocopherol with less antioxidant activity than alpha-tocopherol. It exhibits antioxidant activity by virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus. As in GAMMA-TOCOPHEROL, it also has three methyl groups on the 6-chromanol nucleus but at different sites.

The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.

Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.

A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.

A ubiquitous sodium salt that is commonly used to season food.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.

The rate dynamics in chemical or physical systems.

Measurement of the intensity and quality of fluorescence.

Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.

A photo-active pigment localized in prolamellar bodies occurring within the proplastids of dark-grown bean leaves. In the process of photoconversion, the highly fluorescent protochlorophyllide is converted to chlorophyll.

Derivatives of ACETIC ACID which contain an hydroxy group attached to the methyl carbon.

The pressure required to prevent the passage of solvent through a semipermeable membrane that separates a pure solvent from a solution of the solvent and solute or that separates different concentrations of a solution. It is proportional to the osmolality of the solution.

In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.

Iron-containing proteins that transfer electrons, usually at a low potential, to flavoproteins; the iron is not present as in heme. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

The branch of biology dealing with the effect of light on organisms.

The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.

Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.

Enzymes that catalyze the shifting of a carbon-carbon double bond from one position to another within the same molecule. EC 5.3.3.

A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)

Cytochromes (electron-transporting proteins) with protoheme (HEME B) as the prosthetic group.

A group of GLYCOLIPIDS in which the sugar group is GALACTOSE. They are distinguished from GLYCOSPHINGOLIPIDS in lacking nitrogen. They constitute the majority of MEMBRANE LIPIDS in PLANTS.

Proteins found in the PERIPLASM of organisms with cell walls.

An enzyme that catalyzes the conversion of ATP, L-glutamate, and NH3 to ADP, orthophosphate, and L-glutamine. It also acts more slowly on 4-methylene-L-glutamate. (From Enzyme Nomenclature, 1992) EC 6.3.1.2.