Sarcosine oxidase is a hetero-tetrameric enzyme that contains both covalently bound FMN and non-covalently bound FAD and NAD(+). This enzyme catalyses the oxidative demethylation of sarcosine to yield glycine, H2O2, and 5,10-CH2-tetrahydrofolate (H4folate) in a reaction requiring H4folate and O2 [1,2].

1: Organization of the multiple coenzymes and subunits and role of the covalent flavin link in the complex heterotetrameric sarcosine oxidase. Eschenbrenner M, Chlumsky LJ, Khanna P, Strasser F, Jorns MS; Biochemistry 2001;40:5352-5367. PMID:11330998

2: Sequence analysis of sarcosine oxidase and nearby genes reveals homologies with key enzymes of folate one-carbon metabolism. Chlumsky LJ, Zhang L, Jorns MS; J Biol Chem 1995;270:18252-18259. PMID:7543100