Oligosaccharyltransferase Subunits Bind Polypeptide Substrate to Locally Enhance N-glycosylation

Jamaluddin, M. Fairuz B., Bailey, Ulla-Maja and Schulz, Benjamin L. (2014) Oligosaccharyltransferase Subunits Bind Polypeptide Substrate to Locally Enhance N-glycosylation. Molecular and Cellular Proteomics, 13 12: 3286-3293. doi:10.1074/mcp.M114.041178

Author Jamaluddin, M. Fairuz B.
Bailey, Ulla-Maja
Schulz, Benjamin L.
Title Oligosaccharyltransferase Subunits Bind Polypeptide Substrate to Locally Enhance N-glycosylation
Journal name Molecular and Cellular Proteomics   Check publisher's open access policy
ISSN 1535-9476
Publication date 2014-12
Sub-type Article (original research)
DOI 10.1074/mcp.M114.041178
Open Access Status
Volume 13
Issue 12
Start page 3286
End page 3293
Total pages 8
Place of publication Bethesda, MD United States
Publisher American Society for Biochemistry and Molecular Biology
Collection year 2015
Language eng
Formatted abstract
Oligosaccharyltransferase is a multiprotein complex that catalyzes asparagine-linked glycosylation of diverse proteins. Using yeast genetics and glycoproteomics, we found that transient interactions between nascent polypeptide and Ost3p/Ost6p, homologous subunits of oligosaccharyltransferase, were able to modulate glycosylation efficiency in a site-specific manner in vivo. These interactions were driven by hydrophobic and electrostatic complementarity between amino acids in the peptide-binding groove of Ost3p/Ost6p and the sequestered stretch of substrate polypeptide. Based on this dependence, we used in vivo scanning mutagenesis and in vitro biochemistry to map the precise interactions that affect site-specific glycosylation efficiency. We conclude that transient binding of substrate polypeptide by Ost3p/Ost6p increases glycosylation efficiency at asparagines proximal and C-terminal to sequestered sequences. We detail a novel mode of interaction between translocating nascent polypeptide and oligosaccharyltransferase in which binding to Ost3p/Ost6p segregates a short flexible loop of glycosylation-competent polypeptide substrate that is delivered to the oligosaccharyltransferase active site for efficient modification.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2015 Collection
School of Chemistry and Molecular Biosciences
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Citation counts: TR Web of Science Citation Count  Cited 5 times in Thomson Reuters Web of Science Article | Citations
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Created: Fri, 16 Jan 2015, 11:37:21 EST by Mrs Louise Nimwegen on behalf of School of Chemistry & Molecular Biosciences