Lipopolysaccharide O antigen size distribution is determined by a chain extension complex of variable stoichiometry in Escherichia coli O9a.

ABSTRACT: The lengths of bacterial polysaccharides can be critical for their biological function. Unlike DNA or protein synthesis, where polymer length is implicit in the nucleic acid template, the molecular mechanisms for regulating polysaccharide length are poorly understood. Two models are commonly cited: a "molecular clock" regulates length by controlling the duration of the polymer extension process, whereas a "molecular ruler" determines length by measurement against a physical structure in the biosynthetic complex. Escherichia coli O9a is a prototype for the biosynthesis of O polysaccharides by ATP-binding cassette transporter-dependent processes. The length of the O9a polysaccharide is determined by two proteins: an extension enzyme, WbdA, and a termination enzyme, WbdD. WbdD is known to sel

SUBMITTER: King JD 

PROVIDER: S-EPMC4035927 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature