"Required for polymorphic O-glycosylation of the serine-rich repeat protein in this bacteria. A stabilizing protein that is part of the accessory SecA2/SecY2 system specifically required to export serine-rich repeat cell wall proteins usually encoded upstream in the same operon. The GtfA-GtfB complex adds GlcNAc from UDP-GlcNAc to the substrate protein, attaching the first sugar residue. Stabilizes the glycosylation activity of GtfA. Has no N-acetylglucosaminyl transferase activity on its own."xsd:string