Sarcosine oxidase is a hetero-tetrameric enzyme that contains both covalently bound FMN and non-covalently bound FAD and NAD(+). This enzyme catalyzes the oxidative demethylation of sarcosine to yield glycine, H2O2, and 5,10-CH2-tetrahydrofolate (H4folate) in a reaction requiring H4folate and O2.
Jiyao W et al.(2023). "The conserved domain database in 2023.",