Succinate dehydrogenase, membrane subunit, binds cytochrome b556; Membrane-anchoring subunit of succinate dehydrogenase (SDH).

Succinate dehydrogenase, flavoprotein subunit; Two distinct, membrane-bound, FAD-containing enzymes are responsible for the catalysis of fumarate and succinate interconversion; the fumarate reductase is used in anaerobic growth, and the succinate dehydrogenase is used in aerobic growth.

succinyl-CoA synthetase, beta subunit; Succinyl-CoA synthetase functions in the citric acid cycle (TCA), coupling the hydrolysis of succinyl-CoA to the synthesis of either ATP or GTP and thus represents the only step of substrate-level phosphorylation in the TCA. The beta subunit provides nucleotide specificity of the enzyme and binds the substrate succinate, while the binding sites for coenzyme A and phosphate are found in the alpha subunit. Can use either ATP or GTP, but prefers ATP. It can also function in the other direction for anabolic purposes, and this may be particularly impor [...]

succinyl-CoA synthetase, NAD(P)-binding, alpha subunit; Succinyl-CoA synthetase functions in the citric acid cycle (TCA), coupling the hydrolysis of succinyl-CoA to the synthesis of either ATP or GTP and thus represents the only step of substrate-level phosphorylation in the TCA. The alpha subunit of the enzyme binds the substrates coenzyme A and phosphate, while succinate binding and nucleotide specificity is provided by the beta subunit. Can use either ATP or GTP, but prefers ATP. It can also function in the other direction for anabolic purposes, and this may be particularly importan [...]

Anaerobic fumarate reductase catalytic and NAD/flavoprotein subunit; Two distinct, membrane-bound, FAD-containing enzymes are responsible for the catalysis of fumarate and succinate interconversion; the fumarate reductase is used in anaerobic growth, and the succinate dehydrogenase is used in aerobic growth. Belongs to the FAD-dependent oxidoreductase 2 family. FRD/SDH subfamily.

2-oxoglutarate decarboxylase, thiamine triphosphate-binding; E1 component of the 2-oxoglutarate dehydrogenase (OGDH) complex which catalyzes the decarboxylation of 2-oxoglutarate, the first step in the conversion of 2-oxoglutarate to succinyl-CoA and CO(2).

Dihydrolipoyltranssuccinase; E2 component of the 2-oxoglutarate dehydrogenase (OGDH) complex which catalyzes the second step in the conversion of 2- oxoglutarate to succinyl-CoA and CO(2).

Fumarate hydratase (fumarase A), aerobic Class I; Catalyzes the reversible hydration of fumarate to (S)-malate. Functions as an aerobic enzyme in the direction of malate formation as part of the citric acid cycle. Accounts for about 80% of the fumarase activity when the bacteria grow aerobically. To a lesser extent, also displays D-tartrate dehydratase activity in vitro, but is not able to convert (R)-malate, L-tartrate or meso-tartrate. Can also catalyze the isomerization of enol- to keto-oxaloacetate.

NADH:ubiquinone oxidoreductase, fused CD subunit; NDH-1 shuttles electrons from NADH, via FMN and iron-sulfur (Fe-S) centers, to quinones in the respiratory chain. The immediate electron acceptor for the enzyme in this species is believed to be ubiquinone. Couples the redox reaction to proton translocation (for every two electrons transferred, four hydrogen ions are translocated across the cytoplasmic membrane), and thus conserves the redox energy in a proton gradient; In the C-terminal section; belongs to the complex I 49 kDa subunit family.