A Molecular Chaperone Mediates a Two-protein Enzyme Complex and Glycosylation of Serine-rich Streptococcal Adhesins

摘要: Serine-rich repeat glycoproteins identified from streptococci and staphylococci are important for bacterial adhesion biofilm formation. Two putative glycosyltransferases, Gtf1 Gtf2, Streptococcus parasanguinis form a two-protein enzyme complex that is required glycosylation of serine-rich adhesin, Fap1. glycosyltransferase; however, the function Gtf2 unknown. Here, we demonstrate enhances enzymatic activity by its chaperone-like property. interacted with Gtf1, mediated subcellular localization stabilized Gtf1. Deletion invariable amino acid residues in conserved domain unknown (DUF1975) at N terminus had greater impact on Fap1 than deletion C-terminal non-DUF1975 residues. The DUF1975 deletions concurrently reduced interaction between altered destabilized suggesting crucial chaperone Gtf2. Homologous GtfA GtfB agalactiae rescued defect gtf1gtf2 mutant; like also possesses activity. Taken together, our studies suggest homologs possess molecular mediates protein adhesins.