Reaction: acetyl phosphate + methylamine + thioredoxin disulfide + H2O = N-methylglycine + phosphate + thioredoxin
For diagram click here.
Glossary: sarcosine = N-methylglycine
Systematic name: acetyl-phosphate methylamine:thioredoxin disulfide oxidoreductase (N-methylglycine-forming)
Comments: The reaction is observed only in the direction of sarcosine reduction. The enzyme from Eubacterium acidaminophilum consists of subunits A, B and C. Subunit B contains selenocysteine and a pyruvoyl group, and is responsible for sarcosine binding and methylamine release. Subunit A, which also contains selenocysteine, is reduced by thioredoxin, and is needed to convert the carboxymethyl group into a ketene equivalent, in turn used by subunit C to produce acetyl phosphate. Only subunit B distinguishes this enzyme from EC 126.96.36.199 (glycine reductase) and EC 188.8.131.52 (betaine reductase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 125752-88-7
1. Wagner, M., Sonntag, D., Grimm, R., Pich, A. Eckerskorn, C., Söhling, B. and Andreesen, J.R. Substrate-specific selenoprotein B of glycine reductase from Eubacterium acidaminophilum. Eur. J. Biochem. 260 (1999) 38-49. [PMID: 10091582]
2. Hormann, K. and Andreesen, J.R. Reductive cleavage of sarcosine and betaine by Eubacterium acidaminophilum via enzyme systems different from glycine reductase. Arch. Microbiol. 153 (1989) 50-59.