Energy complex

A bacteriochlorophyll a-CsmA light-harvesting protein-pigment array on one face of green bacterial chlorosomes that accepts excitation energy from chlorosome bacteriochlorophyll aggregates and couples it toward membrane reaction-center complexes.

A purple-bacterial chromatophore membrane cytochrome bc1 protein complex that oxidizes quinol from the chromatophore quinone pool and returns electrons toward reaction-center antenna cores through soluble cytochrome c2 during cyclic photosynthetic electron transport.

A thylakoid membrane protein complex that oxidizes plastoquinol, reduces a downstream soluble electron carrier for photosystem I, and contributes to proton translocation during oxygenic photosynthetic electron transport.

Cytochrome bd-I ubiquinol oxidase complex is a membrane-bound CydAB respiratory terminal oxidase with small bd-I accessory subunits that oxidizes ubiquinol, reduces molecular oxygen to water, and contributes to the respiratory proton motive force.

A four-polypeptide respiratory-chain protein complex that possesses cytochrome o ubiquinol oxidase activity and contains associated prosthetic groups.

A membrane-bound anaerobic dimethyl sulfoxide reductase complex that catalyzes the reduction of dimethyl sulfoxide to dimethyl sulfide during respiratory electron transport.

A nitrate-inducible, membrane-bound formate:quinone oxidoreductase complex whose FdnG, FdnH, and FdnI subunits oxidize formate and pass electrons to a membrane quinone during anaerobic respiration.

A membrane-bound Escherichia coli formate hydrogenlyase complex in which FdhF and HycB-HycG subunits couple formate oxidation to proton reduction, yielding carbon dioxide and hydrogen gas.

A membrane-bound four-subunit respiratory quinol:fumarate reductase complex whose extrinsic catalytic module and membrane-anchor module couple fumarate reduction to quinol oxidation.

A peripheral bacteriochlorophyll-containing light-harvesting antenna protein complex of purple bacterial chromatophore membranes that broadens the photosynthetic absorption cross-section and transfers excitation energy toward RC-LH1 reaction-center core complexes.

A protein-pigment complex that may be closely or peripherally associated to photosynthetic reaction centers that participate in harvesting and transferring radiant energy to the reaction center.

Methyl coenzyme M reductase complex is a hexameric alpha2 beta2 gamma2 enzyme complex that catalyzes coenzyme B-dependent reduction of methyl-coenzyme M to methane during the terminal step of methanogenesis.

A cytoplasmic membrane-bound NarGHI nitrate reductase complex with iron-sulfur, heme, and molybdenum-bis(molybdopterin guanine dinucleotide) cofactors that serves as a terminal reductase during anaerobic nitrate respiration.

A nitrogenase enzyme complex composed of tetrameric dinitrogenase and homodimeric nitrogenase reductase subcomplexes that together catalyze ATP-dependent reduction of dinitrogen to ammonia.

A photosystem that contains an iron-sulfur reaction center associated with accessory pigments and electron carriers. In cyanobacteria and chloroplasts, photosystem I functions as a light-dependent plastocyanin-ferredoxin oxidoreductase, transferring electrons from plastocyanin to ferredoxin; in photosynthetic bacteria that have only a single type I photosystem, such as the green sulfur bacteria, electrons can go either to ferredoxin (Fd) -> NAD+ or to menaquinone (MK) -> Cytb/FeS -> Cytc555 -> photosystem I (cyclic photophosphorylation).

A photosystem that contains a pheophytin-quinone reaction center with associated accessory pigments and electron carriers. In cyanobacteria and chloroplasts, in the presence of light, PSII functions as a water-plastoquinone oxidoreductase, transferring electrons from water to plastoquinone, whereas other photosynthetic bacteria carry out anoxygenic photosynthesis and oxidize other compounds to re-reduce the photoreaction center.

A membrane-associated light-harvesting pigment-protein complex of cyanobacteria and red algae, built from phycobiliprotein core and rod cylinders plus linker polypeptides, that funnels phycobilin excitation energy to photosynthetic reaction centers.

Allophycocyanin-containing central cylinder assembly of a phycobilisome that receives excitation energy from peripheral rods and routes it toward chlorophyll photosystems.

Peripheral phycobiliprotein cylinder subassembly of a phycobilisome that binds phycobilin chromophores, absorbs excitation energy, and transfers it inward to the allophycocyanin core.

A photosystem I protein complex located in the plasma membrane-derived bacterial thylakoid membrane.

A photosystem II protein complex located in the plasma membrane-derived bacterial thylakoid that contains a P680 reaction center and catalyzes the water-oxidizing, plastoquinone-reducing step of oxygenic photosynthesis.

The rotary motor enzyme that makes ATP from ADP and phosphate using the ion motive force across the membrane. It has two coupled sectors: a membrane-embedded Fo, whose c-ring turns as protons cross it, and a soluble F1 (alpha3beta3gammadeltaepsilon), whose catalytic beta subunits are driven through their conformational cycle by the rotating gamma subunit.

A purple-bacterial chromatophore membrane protein complex that contains a photochemical reaction center, LH1 antenna proteins and PufX, receives excitation from surrounding LH2 antennae, and reduces quinone during cyclic photosynthetic electron transport.

Respiratory chain complex I is an L-shaped enzyme of the respiratory chain that oxidizes NADH, routes electrons through a hydrophilic peripheral arm to quinone, and couples quinone reduction to proton translocation through a membrane arm.

Respiratory chain complex II (succinate dehydrogenase) is a respiratory-chain enzyme complex that oxidizes succinate, passes electrons through flavin and iron-sulfur centers to membrane quinone, and thereby connects tricarboxylic-acid-cycle electron flow with the respiratory quinone pool.

Respiratory chain complex III is a membrane-bound cytochrome bc1 oxidoreductase complex that uses a cytochrome b, Rieske iron-sulfur protein, and cytochrome c1 catalytic core to transfer electrons from quinol to cytochrome c while translocating protons.

Respiratory chain complex IV is a membrane-bound cytochrome c oxidase complex that transfers electrons from reduced cytochrome c to dioxygen and couples oxygen reduction to proton translocation across a respiratory membrane.

Sodium-translocating NADH:quinone reductase complex is a bacterial respiratory-chain protein complex composed of NqrA, NqrB, NqrC, NqrD, NqrE, and NqrF that transfers electrons from NADH to ubiquinone while exporting sodium ions across the cytoplasmic membrane.

A proton-transporting two-sector ATPase complex found in the vacuolar membrane, where it acts as a proton pump to mediate acidification of the vacuolar lumen.

The V0 domain of a proton-transporting V-type ATPase found in the vacuolar membrane.

The V1 domain of a proton-transporting V-type ATPase found in the vacuolar membrane.