title: Structure and gene cluster of the o-antigen of Escherichia coli o96.
abstract: 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.
authors.affiliation: TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457 Tianjin, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Guo
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia.
authors.forename: Sof'ya N
authors.initials: SN
authors.lastname: Senchenkova
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia. Electronic address: perepel@ioc.ac.ru.
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Perepelov
authors.affiliation: TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457 Tianjin, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia.
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
mesh_terms: D066241:Carbon-13 Magnetic Resonance Spectroscopy; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics; D015394:Molecular Structure; D005810:Multigene Family; D019081:O Antigens / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D066244:Proton Magnetic Resonance Spectroscopy
chemical_list: D029968:Escherichia coli Proteins; D019081:O Antigens
keywords: Bacterial polysaccharide structure; Escherichia coli; O-antigen; O-polysaccharide; O–antigen gene cluster; Peptidoglycan-related polysaccharide