Genome Property Definition Page

Namepyruvate conversion to propionate, anaerobic, FAD/NAD-regenerating
DescriptionCertain bacteria (notably Propionobacter species) convert pyruvate to propionate as a waste end-product of anaerobic fermentation. The purpose of this pathway is to regenerate the NADH and FADH2 consumed in the production of pyruvate (and ATP) from fermentable sugars, something that cannot be done efficiently in the absence of oxygen or other suitable electron acceptor. The essential enzyme in this pathway is methylmalonyl-CoA carboxytransferase (EC which couples the carboxylation of pyruvate (to oxaloacetate) with the decarboxylation of (S)-methylmalonyl-CoA (to propionyl-CoA). Without this enzyme the conversion of pyruvate to oxaloacetate would require ATP (EC and be considerably less efficient. Note that a number of the components of this pathway are also elements of the TCA cycle running in reverse (malate DH, fumarate hydratase, succinate dehydrogenase).
Parent PropertyGenProp0070: energy metabolism
Web ReferencesMetaCyc:pyruvate fermentation to propionate I

Step NameStep NumRequiredEvidence (Method)Evidence Go Terms
fumarate hydratase ( (HMM): fumarate hydratase, class II
PF05683 (HMM): fumarate hydratase I, C-terminal region or beta subunit
PF05681 (HMM): fumarate hydratase
fumarate reductase complexFRDYESGenProp0756 (GENPROP): fumarate reductase complex
malate dehydrogenase ( (HMM): malate dehydrogenase
TIGR01758 (HMM): malate dehydrogenase, NAD-dependent
TIGR01763 (HMM): malate dehydrogenase, NAD-dependent
TIGR01772 (HMM): malate dehydrogenase, NAD-dependent
methylmalonyl-CoA decarboxylaseMMC-DCYES
methylmalonyl-CoA epimerase ( (HMM): methylmalonyl-CoA epimerase
methylmalonyl-CoA mutase ( (HMM): methylmalonyl-CoA mutase N-terminal domain
TIGR00640 (HMM): methylmalonyl-CoA mutase C-terminal domain
TIGR00642 (HMM): methylmalonyl-CoA mutase, small subunit
pyruvate carboxylasePCYES
propionyl CoA:succinate CoA transferase (2.8.3.-)PCSCTYESTIGR03458 (HMM): succinate CoA transferase

Parent Properties
GenProp0070energy metabolism

Sibling Properties
GenProp0023glyoxylate shunt
GenProp0033TCA cycle
GenProp0120pentose phosphate cycle
GenProp0131electron transport
GenProp0243ATP synthases
GenProp0459D-xylose utilization (conversion to D-xylulose-5-phosphate)
GenProp0468Entner-Doudoroff pathway
GenProp0473arsenite oxidase
GenProp0611aerobic respiration
GenProp0636respiratory nitrate reductase
GenProp0637anaerobic dimethyl sulfoxide reductase
GenProp0638trimethylamine N-oxide reductase system
GenProp0682formate-dependent nitrite reductase, seven-gene type
GenProp0683cytochrome c nitrite reductase NrfHA
GenProp0695cytochrome b558/566
GenProp0723hydrogenase, nickel and F420-dependent
GenProp0737anaerobic glycerol-3-phosphate dehydrogenase complex
GenProp0756fumarate reductase complex
GenProp0764DMSO reductase family type II enzyme
GenProp08412-oxoacid:ferredoxin oxidoreductase
GenProp0856bacterio-opsin system
GenProp0914hydrogenase, [FeFe]-dependent
GenProp0915hydrogenase, mono-iron type
GenProp1089B12-dependent trimeric diol/glycerol dehydratase