<p>These sequences represent the beta subunit of a family of known and putative heterotetrameric sarcosine oxidases. Five operons of such oxidases are found in <taxon tax_id="381">Rhizobium loti</taxon> (Mesorhizobium loti) and three in <taxon tax_id="358">Agrobacterium tumefaciens</taxon>, a high enough copy number to suggest that not all members share the same function. The model is designated as subfamily rather than equivalog for this reason. </p><p>Sarcosine oxidase catalyzes the oxidative demethylation of sarcosine to glycine. The reaction converts tetrahydrofolate to 5,10-methylene-tetrahydrofolate [<cite idref="PUB00033240"/>]. Bacterial sarcosine oxidases have been isolated from over a dozen different organisms and fall into two major classes (1) monomeric form that contains only covalent flavin and (2) heterotetrameric (alpha, beta, gamma, delta) forms that contain a covalent and noncovalent flavin, this entry represents the heterotetrameric form.</p> Sarcosine oxidase, beta subunit, heterotetrameric