Structure and gene cluster of the o-antigen of Escherichia coli o96

Carbohydr Res. 2016 Feb;420:1-5. doi: 10.1016/j.carres.2015.11.005. Epub 2015 Nov 23.


Mild acid degradation of the lipopolysaccharide of Escherichia coli O96 afforded a mixture of two polysaccharides. The following structure of the pentasaccharide repeating unit of the major polymer was established by sugar analysis, Smith degradation, and (1)H and (13)C NMR spectroscopy: [Formula: see text]. The O-antigen gene cluster of E. coli O96 between conserved galF and gnd genes was found to be consistent with this structure, and hence, the major polysaccharide represents the O96-antigen. The O96-antigen structure and gene cluster are similar to those of E. coli O170, and two proteins encoded in the gene clusters of both bacteria were putatively assigned a function of galactofuranosyltransferases. The minor polymer has the same structure as a peptidoglycan-related polysaccharide reported earlier in Providencia alcalifeciens O45 and several other O-serogoups of this species (Ovchinnikova OG, Liu B, Kocharova NA, Shashkov AS, Kondakova AN, Siwinska M, Feng L, Rozalski A, Wang L, Knirel YA. Biochemistry (Moscow) 2012;77:609-15) → 4)-β-D-GlcpNAc-(1 → 4)-β-D-GlcpNAc3(Rlac-lAla)-(1 → where Rlac-lAla indicates (R)-1-[(S)-1-carboxyethylaminocarbonyl]ethyl.

Keywords: Bacterial polysaccharide structure; Escherichia coli; O-antigen; O-polysaccharide; O–antigen gene cluster; Peptidoglycan-related polysaccharide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon-13 Magnetic Resonance Spectroscopy
  • Escherichia coli / chemistry
  • Escherichia coli / genetics*
  • Escherichia coli Proteins / chemistry
  • Escherichia coli Proteins / genetics
  • Molecular Structure
  • Multigene Family
  • O Antigens / chemistry*
  • O Antigens / genetics*
  • O Antigens / isolation & purification
  • Phylogeny
  • Proton Magnetic Resonance Spectroscopy


  • Escherichia coli Proteins
  • O Antigens