Glycine metabolism in anaerobes

Some strict anaerobic bacteria catalyze with glycine as substrate an internal Stickland reaction by which glycine serves as electron donor being oxidized by glycine-cleavage system or as electron acceptor being reduced by glycine reductase. In both cases, energy is conserved by substrate level phosphorylation. Except for the different substrate-activating proteins P_B, reduction of sarcosine or betaine to acetyl phosphate involves inEubacterium acidaminophilum the same set of proteins as observed for glycine, e.g. a unique thioredoxin system as electron donor and an acetyl phosphate-forming protein P_c interacting with the intermediarily formed Secarboxymethylselenoether bound to protein P_A.