Mutational analysis of the Shigella flexneri O-antigen polymerase Wzy: identification of Wzz-dependent Wzy mutants.

ABSTRACT: The O-antigen (Oag) component of lipopolysaccharide (LPS) is a major virulence determinant of Shigella flexneri and is synthesized by the O-antigen polymerase, WzySf. Oag chain length is regulated by chromosomally encoded WzzSf and pHS-2 plasmid-encoded WzzpHS2. To identify functionally important amino acid residues in WzySf, random mutagenesis was performed on the wzySf gene in a pWaldo-TEV-GFP plasmid, followed by screening with colicin E2. Analysis of the LPS conferred by mutated WzySf proteins in the wzySf-deficient (Δwzy) strain identified 4 different mutant classes, with mutations found in periplasmic loop 1 (PL1), PL2, PL3, and PL6, transmembrane region 2 (TM2), TM4, TM5, TM7, TM8, and TM9, and cytoplasmic loop 1 (CL1) and CL5. The association of WzySf and WzzSf was investigated by

SUBMITTER: Nath P 

PROVIDER: S-EPMC4288684 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature