7MSN

SunS glycosin S-glycosyltransferase

Summary for 7MSN

• Entry DOI: 10.2210/pdb7msn/pdb
• Related: 7MSK
• Descriptor: SPbeta prophage-derived glycosyltransferase SunS, URIDINE-5'-DIPHOSPHATE-GLUCOSE (2 entities in total)
• Functional Keywords: glycosin, ripp, s-glycosyltransferase, biosynthetic protein, transferase
• Biological source: Bacillus subtilis (strain 168)
• Total number of polymer chains: 2
• Total formula weight: 100794.09

Authors

Garg, N.,Nair, S.K. (deposition date: 2021-05-11, release date: 2022-04-13, Last modification date: 2024-05-22)

Primary citation

Fujinami, D.,Garcia de Gonzalo, C.V.,Biswas, S.,Hao, Y.,Wang, H.,Garg, N.,Lukk, T.,Nair, S.K.,van der Donk, W.A.
Structural and mechanistic investigations of protein S-glycosyltransferases.
Cell Chem Biol, 28:1740-1749.e6, 2021

PubMed Abstract: Attachment of sugars to nitrogen and oxygen in peptides is ubiquitous in biology, but glycosylation of sulfur atoms has only been recently described. Here, we characterize two S-glycosyltransferases SunS and ThuS that selectively glycosylate one of five Cys residues in their substrate peptides; substitution of this Cys with Ser results in a strong decrease in glycosylation activity. Crystal structures of SunS and ThuS in complex with UDP-glucose or a derivative reveal an unusual architecture in which a glycosyltransferase type A (GTA) fold is decorated with additional domains to support homodimerization. Dimer formation creates an extended cavity for the substrate peptide, drawing functional analogy with O-glycosyltransferases involved in cell wall biosynthesis. This extended cavity contains a sharp bend that may explain the site selectivity of the glycosylation because the target Cys is in a Gly-rich stretch that can accommodate the bend. These studies establish a molecular framework for understanding the unusual S-glycosyltransferases.

PubMed: 34283964
DOI: 10.1016/j.chembiol.2021.06.009

Experimental method

X-RAY DIFFRACTION (3 Å)