title: Structure and characterization of the gene cluster of the O-antigen of Escherichia coli O49 containing 4,6-dideoxy-4-[(S)-3-hydroxybutanoylamino]-D-glucose.
abstract: An O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of enteropathogenic Escherichia coli O49 and studied by sugar analysis along with one- and two-dimensional 1H- and 13C-NMR spectroscopy. The following structure of the linear tetrasaccharide repeating unit of the O-polysaccharide was established: [formula], where D-Qui4N(S3HOBut) stands for 4,6-dideoxy-4-[(S)-3-hydroxybutanoylamino]-D-glucose and O-acetylation of GlcNAc is partial (~30%). To our knowledge, no N-(3-hydroxybutanoyl) derivative of Qui4N has been hitherto found in bacterial polysaccharides. Gene functions of the O-antigen gene cluster of E. coli O49 were assigned by bioinformatics analysis and found to correspond to the O-polysaccharide structure. Two new genes were revealed and suggested to be responsible for synthesis and transfer of the 3-hydroxybutanoyl group.
authors.affiliation: Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 119991, Russia. perepel@ioc.ac.ru
authors.forename: A V
authors.initials: AV
authors.lastname: Perepelov
authors.forename: Quan
authors.initials: Q
authors.lastname: Wang
authors.forename: S N
authors.initials: SN
authors.lastname: Senchenkova
authors.forename: S D
authors.initials: SD
authors.lastname: Shevelev
authors.forename: A S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Lu
authors.initials: L
authors.lastname: Feng
authors.forename: Y A
authors.initials: YA
authors.lastname: Knirel
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
mesh_terms: D002240:Carbohydrate Sequence; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000737:chemistry; D004798:Enzymes / Q000235:genetics; D004926:Escherichia coli / Q000145:classification* / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D019081:O Antigens / Q000096:biosynthesis / Q000737:chemistry*
chemical_list: D004798:Enzymes; D029968:Escherichia coli Proteins; D019081:O Antigens; D003847:Deoxyglucose