Structural and Biochemical Analysis of a Single Amino-Acid Mutant of WzzBSF That Alters Lipopolysaccharide O-Antigen Chain Length in Shigella flexneri.

Bibliographic Details
Title: Structural and Biochemical Analysis of a Single Amino-Acid Mutant of WzzBSF That Alters Lipopolysaccharide O-Antigen Chain Length in Shigella flexneri.
Authors: Chiung-Wen Chang, Elizabeth N H Tran, Daniel J Ericsson, Lachlan W Casey, Thierry Lonhienne, Friederike Benning, Renato Morona, Bostjan Kobe
Source: PLoS ONE, Vol 10, Iss 9, p e0138266 (2015)
Publisher Information: Public Library of Science (PLoS), 2015.
Publication Year: 2015
Collection: LCC:Medicine
LCC:Science
Subject Terms: Medicine, Science
More Details: Lipopolysaccharide (LPS), a surface polymer of Gram-negative bacteria, helps bacteria survive in different environments and acts as a virulence determinant of host infection. The O-antigen (Oag) component of LPS exhibits a modal chain-length distribution that is controlled by polysaccharide co-polymerases (PCPs). The molecular basis of the regulation of Oag chain-lengths remains unclear, despite extensive mutagenesis and structural studies of PCPs from Escherichia coli and Shigella. Here, we identified a single mutation (A107P) of the Shigella flexneri WzzBSF, by a random mutagenesis approach, that causes a shortened Oag chain-length distribution in bacteria. We determined the crystal structures of the periplasmic domains of wild-type WzzBSF and the A107P mutant. Both structures form a highly similar open trimeric assembly in the crystals, and show a similar tendency to self-associate in solution. Binding studies by bio-layer interferometry reveal cooperative binding of very short (VS)-core-plus-O-antigen polysaccharide (COPS) to the periplasmic domains of both proteins, but with decreased affinity for the A107P mutant. Our studies reveal that subtle and localized structural differences in PCPs can have dramatic effects on LPS chain-length distribution in bacteria, for example by altering the affinity for the substrate, which supports the role of the structure of the growing Oag polymer in this process.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1932-6203
Relation: http://europepmc.org/articles/PMC4574919?pdf=render; https://doaj.org/toc/1932-6203
DOI: 10.1371/journal.pone.0138266
Access URL: https://doaj.org/article/8c68ee9d58cf4c319f596c02a271ed8d
Accession Number: edsdoj.8c68ee9d58cf4c319f596c02a271ed8d
Database: Directory of Open Access Journals
More Details
ISSN:19326203
DOI:10.1371/journal.pone.0138266
Published in:PLoS ONE
Language:English