Rhodobacter capsulatus: Non-pathogenic ovoid to rod-shaped bacteria that are widely distributed and found in fresh water as well as marine and hypersaline habitats.Rhodobacter: A genus of gram-negative bacteria widely distributed in fresh water as well as marine and hypersaline habitats.Cytochromes c2: Type C cytochromes that are small (12-14 kD) single-heme proteins. They function as mobile electron carriers between membrane-bound enzymes in photosynthetic BACTERIA.Bacteriochlorophylls: Pyrrole containing pigments found in photosynthetic bacteria.Methylococcus capsulatus: A species of METHYLOCOCCUS which forms capsules and is capable of autotrophic carbon dioxide fixation. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Rhodopseudomonas: A genus of gram-negative, rod-shaped, phototrophic bacteria found in aquatic environments. Internal photosynthetic membranes are present as lamellae underlying the cytoplasmic membrane.Photosynthetic Reaction Center Complex Proteins: 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.Bacterial Proteins: Proteins found in any species of bacterium.Photosynthesis: 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)Genes, Bacterial: The functional hereditary units of BACTERIA.Nitrogenase: An enzyme system that catalyzes the fixing of nitrogen in soil bacteria and blue-green algae (CYANOBACTERIA). EC 220.127.116.11.Molybdenum: A metallic element with the atomic symbol Mo, atomic number 42, and atomic weight 95.94. It is an essential trace element, being a component of the enzymes xanthine oxidase, aldehyde oxidase, and nitrate reductase. (From Dorland, 27th ed)Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Rhodospirillaceae: A family of phototrophic bacteria, in the order Rhodospirillales, isolated from stagnant water and mud.Molecular Sequence Data: 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.Light-Harvesting Protein Complexes: 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.Bacterial Chromatophores: Organelles of phototrophic bacteria which contain photosynthetic pigments and which are formed from an invagination of the cytoplasmic membrane.Operon: 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.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Electron Transport Complex III: A multisubunit enzyme complex that contains CYTOCHROME B GROUP; CYTOCHROME C1; and iron-sulfur centers. It catalyzes the oxidation of ubiquinol to UBIQUINONE, and transfers the electrons to CYTOCHROME C. In MITOCHONDRIA the redox reaction is coupled to the transport of PROTONS across the inner mitochondrial membrane.Amino Acid Sequence: 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.Cytochrome c Group: A group of cytochromes with covalent thioether linkages between either or both of the vinyl side chains of protoheme and the protein. (Enzyme Nomenclature, 1992, p539)Tetrapyrroles: 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.Methylococcaceae: A family of gram-negative, aerobic bacteria utilizing only one-carbon organic compounds and isolated from in soil and water.Aerobiosis: Life or metabolic reactions occurring in an environment containing oxygen.Cytochromes c1: The 30-kDa membrane-bound c-type cytochrome protein of mitochondria that functions as an electron donor to CYTOCHROME C GROUP in the mitochondrial and bacterial RESPIRATORY CHAIN. (From Enzyme Nomenclature, 1992, p545)Nitrogen Fixation: The process in certain BACTERIA; FUNGI; and CYANOBACTERIA converting free atmospheric NITROGEN to biologically usable forms of nitrogen, such as AMMONIA; NITRATES; and amino compounds.Iron-Sulfur Proteins: A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Electron Transport: 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)Oxidation-Reduction: 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).Hydrogenase: An enzyme found in bacteria. It catalyzes the reduction of FERREDOXIN and other substances in the presence of molecular hydrogen and is involved in the electron transport of bacterial photosynthesis.Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Ferredoxins: 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)Xanthine Dehydrogenase: An enzyme that catalyzes the oxidation of XANTHINE in the presence of NAD+ to form URIC ACID and NADH. It acts also on a variety of other purines and aldehydes.PII Nitrogen Regulatory Proteins: A family of signal transducing adaptor proteins that control the METABOLISM of NITROGEN. They are primarily found in prokaryotes.Carotenoids: 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.Genetic Complementation Test: 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.Cosmids: Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Phototrophic Processes: 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.Cloning, Molecular: 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.Tellurium: Tellurium. An element that is a member of the chalcogen family. It has the atomic symbol Te, atomic number 52, and atomic weight 127.60. It has been used as a coloring agent and in the manufacture of electrical equipment. Exposure may cause nausea, vomiting, and CNS depression.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Rhodobacter sphaeroides: Spherical phototrophic bacteria found in mud and stagnant water exposed to light.Mutation: 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.Escherichia coli: 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.Pteridines: Compounds based on pyrazino[2,3-d]pyrimidine which is a pyrimidine fused to a pyrazine, containing four NITROGEN atoms.Flavodoxin: A low-molecular-weight (16,000) iron-free flavoprotein containing one molecule of flavin mononucleotide (FMN) and isolated from bacteria grown on an iron-deficient medium. It can replace ferredoxin in all the electron-transfer functions in which the latter is known to serve in bacterial cells.Coenzymes: Small molecules that are required for the catalytic function of ENZYMES. Many VITAMINS are coenzymes.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.AcetyleneDithionite: Dithionite. The dithionous acid ion and its salts.Bacterial Proton-Translocating ATPases: Membrane-bound proton-translocating ATPases that serve two important physiological functions in bacteria. One function is to generate ADENOSINE TRIPHOSPHATE by utilizing the energy provided by an electrochemical gradient of protons across the cellular membrane. A second function is to counteract a loss of the transmembrane ion gradient by pumping protons at the expense of adenosine triphosphate hydrolysis.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Oxidoreductases Acting on CH-CH Group Donors: A subclass of enzymes which includes all dehydrogenases acting on carbon-carbon bonds. This enzyme group includes all the enzymes that introduce double bonds into substrates by direct dehydrogenation of carbon-carbon single bonds.Pterins: Compounds based on 2-amino-4-hydroxypteridine.Neutral Red: A vital dye used as an indicator and biological stain. Various adverse effects have been observed in biological systems.2,4-Dinitrophenol: A toxic dye, chemically related to trinitrophenol (picric acid), used in biochemical studies of oxidative processes where it uncouples oxidative phosphorylation. It is also used as a metabolic stimulant. (Stedman, 26th ed)Metalloproteins: Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)Kinetics: The rate dynamics in chemical or physical systems.Plasmids: 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.2,6-Dichloroindophenol: A dye used as a reagent in the determination of vitamin C.Electron Transport Complex IV: A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Oxygen: 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.Spectrum Analysis: The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Proton-Motive Force: Energy that is generated by the transfer of protons or electrons across an energy-transducing membrane and that can be used for chemical, osmotic, or mechanical work. Proton-motive force can be generated by a variety of phenomena including the operation of an electron transport chain, illumination of a PURPLE MEMBRANE, and the hydrolysis of ATP by a proton ATPase. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed, p171)Xanthobacter: A genus of gram-negative, aerobic, rod-shaped bacteria found in wet soil containing decaying organic material and in water. Cells tend to be pleomorphic if grown on media containing succinate or coccoid if grown in the presence of an alcohol as the sole carbon source. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Heme: The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.Open Reading Frames: 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).Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.FlavoproteinsProtoporphyrins: Porphyrins with four methyl, two vinyl, and two propionic acid side chains attached to the pyrrole rings. Protoporphyrin IX occurs in hemoglobin, myoglobin, and most of the cytochromes.Mutagenesis, Insertional: 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.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.