Size of E. coli O9a O polysaccharide (number of domains containing 4 mannoses)

Range 13 - 14 domain repeats
Organism Bacteria Escherichia coli
Reference King JD et al., Lipopolysaccharide O antigen size distribution is determined by a chain extension complex of variable stoichiometry in Escherichia coli O9a. Proc Natl Acad Sci U S A. 2014 Apr 29111(17):6407-12. doi: 10.1073/pnas.1400814111. p.6408 figure 1BPubMed ID24733938
Method p.6408 right column 2nd paragraph:"In this study [investigators] show that E. coli O9a OPS length distribution can be quantitatively modulated by titrating the expression of either of the biosynthetic enzymes, WbdD and WbdA."
Comments p.6407 left column 3rd paragraph:"Lipopolysaccharide (LPS) is a glycolipid which constitutes the major and characteristic component of the outer leaflet of the outer membrane of most Gram negative bacterial cell envelopes (reviewed in ref. 1). Most bacteria produce LPS molecules that contain a conserved lipid A moiety linked to a short (core) oligosaccharide. In many species, a proportion of LPS molecules have an additional domain known as O polysaccharide (OPS), O antigen or O chain. OPS is a carbohydrate polymer in which the repeating unit (O unit) consists of a short oligosaccharide or sometimes a single sugar. OPS is synthesized template-free by glycosyltransferases and is found in lengths that vary from one repeat unit to several hundred sugars." p.6408 left column 2nd paragraph:"The prototype for the ABC transporter-dependent pathway is the OPS from Escherichia coli O9a. This OPS has a four-sugar repeat unit containing a 1 ? 2, and a 1 ? 3-linked D -mannose (Fig. 1 C ) (ref 10) with a unimodal chain-length distribution (Fig. 1 B ). Biosynthesis of the repeating domain of this OPS is catalyzed by WbdA, a chain extension enzyme containing two glycosyltransferase domains (ref 11)."
Entered by Uri M
ID 111526