UDP-N-acetylglucosamine--peptide N-acetylglucosaminyltransferase GtfA subunit

UniProtKB accession:  Q9AET5

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Required for polymorphic O-glycosylation of GspB, a serine-rich repeat cell wall protein encoded upstream in the same operon. Catalyzes the first step in glycosylation by transferring N-acetylglucosamine from UDP-GlcNAc to serine residues in GspB. Part of the accessory SecA2/SecY2 system specifically required to export GspB. Upon coexpression in E.coli with GtfB glycosylates GspB constructs. Glycosylation probably occurs intracellularly (PubMed:15489421). Requires GtfB for glycosylation activity, it has no activity alone. Does not use UDP-glucose as substrate. Has a fast, probably processive glycosylation phase followed by a slower, non-processive phase. The enzyme probably modifies its tertiary conformation by opening and closing its intersubunit interfaces to accomodate the increasingly glycosylated substrate; protein substrate recognition is provided by GtfB (PubMed:26884191).