5HEC

CgT structure in dimer

Summary for 5HEC

• Entry DOI: 10.2210/pdb5hec/pdb
• Related: 5HEA
• Descriptor: Putative glycosyltransferase (GalT1) (2 entities in total)
• Functional Keywords: glycosyltransferase, helix binding domain, transferase
• Biological source: Streptococcus parasanguinis FW213
• Total number of polymer chains: 2
• Total formula weight: 68589.29

Authors

Zhang, H.,Wu, H. (deposition date: 2016-01-05, release date: 2016-08-31, Last modification date: 2024-10-09)

Primary citation

Zhang, H.,Zhou, M.,Yang, T.,Haslam, S.M.,Dell, A.,Wu, H.
New Helical Binding Domain Mediates a Glycosyltransferase Activity of a Bifunctional Protein.
J.Biol.Chem., 291:22106-22117, 2016

PubMed Abstract: Serine-rich repeat glycoproteins (SRRPs) conserved in streptococci and staphylococci are important for bacterial colonization and pathogenesis. Fap1, a well studied SRRP is a major surface constituent of Streptococcus parasanguinis and is required for bacterial adhesion and biofilm formation. Biogenesis of Fap1 is a multistep process that involves both glycosylation and secretion. A series of glycosyltransferases catalyze sequential glycosylation of Fap1. We have identified a unique hybrid protein dGT1 (dual glycosyltransferase 1) that contains two distinct domains. N-terminal DUF1792 is a novel GT-D-type glycosyltransferase, transferring Glc residues to Glc-GlcNAc-modified Fap1. C-terminal dGT1 (CgT) is predicted to possess a typical GT-A-type glycosyltransferase, however, the activity remains unknown. In this study, we determine that CgT is a distinct glycosyltransferase, transferring GlcNAc residues to Glc-Glc-GlcNAc-modified Fap1. A 2.4-Å x-ray crystal structure reveals that CgT has a unique binding domain consisting of three α helices in addition to a typical GT-A-type glycosyltransferase domain. The helical domain is crucial for the oligomerization of CgT. Structural and biochemical studies revealed that the helix domain is required for the protein-protein interaction and crucial for the glycosyltransferase activity of CgT in vitro and in vivo As the helix domain presents a novel structural fold, we conclude that CgT represents a new member of GT-A-type glycosyltransferases.

PubMed: 27539847
DOI: 10.1074/jbc.M116.731695

Experimental method

X-RAY DIFFRACTION (2.395 Å)