Unraveling the sequence of cytosolic reactions in the export of GspB adhesin from Streptococcus gordonii
Year: 2018
Type: article
Abstract: ABSTRACT Many pathogenic bacteria, including Streptococcus gordonii , possess a pathway for the export of a single serine-rich-repeat protein that mediates the adhesion of bacteria to host cells and the extracellular matrix. These adhesins are O -glycosylated by several cytosolic glycosyltransferases and require three accessory Sec proteins (Asp1-3) for export, but how the adhesins are processed for secretion is not well defined. Here, we show that O -glycosylation of S. gordonii adhesin GspB occurs in a sequential manner by three enzymes (GtfA/B, Nss, Gly) that attach N-acetylglucosamine and glucose to Ser/Thr residues. The modified substrate is subsequently transferred from the last glycosyltransferase to the Asp1/2/3 complex. Crystal structures show that both Asp1 and Asp3 are related to carbohydrate binding proteins. Asp1 also has an affinity for phospholipids, which is attenuated by Asp2. These results suggest a mechanism for the modification of adhesin in the cytosol and its subsequent targeting to the export machinery.
Source: Journal of Biological Chemistry
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
Funders: Howard Hughes Medical Institute, U.S. Department of Energy, U.S. Department of Veterans Affairs, Helen Hay Whitney Foundation, Northern California Institute for Research and Education, National Institutes of Health, Office of Science, National Institute of General Medical Sciences, National Institute of Allergy and Infectious Diseases, National Center for Research Resources, Office of Research Infrastructure Programs, National Institutes of Health, Argonne National Laboratory
Awards: G102163711, G107546177, G1313983767, G1505794299, G1664757510, G2101401529, G2164036156, G222768804, G2287611682, G2512394855, G254657075, G262962599, NEW AWARD - THE CENTER FOR PLANT AND MICROBIAL COMPLEX CARBOHYDRATES AT THE UNIVERSITY OF GEORGIA COMPLEX CARBOHYDRATE RESEARCH CENTER, G2887060908, G2892807577, G3075337988, Pixel Array Detector for X-ray Crystallography, G340565428, G3407338877, G409777406, G4525802209, G498139845, G5106849484, G5201631574, TAS::89 0222::TAS CENTER FOR PLANT AND MICROBIAL COMPLEX CARBOHYDRATES, G5341054486, Orbitrap Fusion Tribrid Mass Spectrometer, G5607048534, G6168668500, G666778509, G6848031779, G6918803902, G7368700025, Mechanisms for ligand binding by serine-rich adhesins of Gram-positive pathogens, Role of Streptococcal-Platelet Binding in Endocarditis, NATIONAL CENTER FOR BIOMEDICAL GLYCOMICS , NE-CAT Center for Advanced Macromolecular Crystallography, G9000119994, G9000240547, G9000331662, Molecular Mechanisms of Channels and Transporters, Protein Transport Across Membranes, THE CENTER FOR PLANT AND MICROBIAL COMPLEX CARBOHYDRATES AT THE UNIVERSITY OF GEORGIA COMPLEX CARBOHYDRATE RESEARCH CENTER, G969889393, G993149817
OpenAlex ID: W2786690884