Members of this protein family are putative glycosyltransferases, members of pfam00535 (glycosyl transferase family 2). Members appear mostly in the Actinobacteria, where they appear to be part of a system for converting a precursor peptide (TIGR03969) into a novel redox carrier designated mycofactocin. A radical SAM enzyme, TIGR03962, is a proposed to be a key maturase for mycofactocin.