4ZM5

Shigella flexneri lipopolysaccharide O-antigen chain-length regulator WzzBSF - A107P mutant

Summary for 4ZM5

• Entry DOI: 10.2210/pdb4zm5/pdb
• Related: 4ZM1
• Descriptor: Chain length determinant protein, CHLORIDE ION, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: lipopolysaccharide, chain-length, virulence, serospecificity, membrane protein
• Biological source: Shigella flexneri
• Cellular location: Cell inner membrane; Multi-pass membrane protein: P37792
• Total number of polymer chains: 3
• Total formula weight: 82838.59

Authors

Ericsson, D.J.,Chang, C.-W.,Lonhienne, T.,Casey, L.,Benning, F.,Kobe, B.,Tran, E.N.H.,Morona, R. (deposition date: 2015-05-02, release date: 2016-03-23, Last modification date: 2023-09-27)

Primary citation

Chang, C.W.,Tran, E.N.,Ericsson, D.J.,Casey, L.W.,Lonhienne, T.,Benning, F.,Morona, R.,Kobe, B.
Structural and Biochemical Analysis of a Single Amino-Acid Mutant of WzzBSF That Alters Lipopolysaccharide O-Antigen Chain Length in Shigella flexneri.
Plos One, 10:e0138266-e0138266, 2015

PubMed Abstract: 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.

PubMed: 26378781
DOI: 10.1371/journal.pone.0138266

Experimental method

X-RAY DIFFRACTION (2.47 Å)