title: Structure of the β-l-fucopyranosyl phosphate-containing O-specific polysaccharide of Escherichia coli O84.
abstract: Fine structure of the O-polysaccharide chain of the lipopolysaccharide (O-antigen) defines the serospecificity of bacterial cells, which is the basis for O-serotyping of medically and agriculturally important gram-negative bacteria including Escherichia coli. In order to obtain the O-polysaccharide for structural analysis, the lipopolysaccharide was isolated from cells of E. coli O84a by phenol/water extraction and degraded with mild acid. However, the O-polysaccharide was cleaved at a highly acid-labile β-l-fucopyranosyl phosphate (β-l-Fucp-1-P) linkage to give mainly a pentasaccharide that corresponded to the O-polysaccharide repeat. Therefore, the lipopolysaccharide and the pentasaccharide as well as their O-deacylated derivatives were studied using sugar analysis, NMR spectroscopy, and (for oligosaccharides) ESI HR MS, and the O84-polysaccharide structure was established. The O-polysaccharide is distinguished by the presence of β-l-Fucp-1-P and randomly di-O-acetylated 6-deoxy-d-talose, which are found for the first time in natural carbohydrates. The gene cluster for the O84-antigen biosynthesis was analysed and its content was found to be consistent with the O-polysaccharide structure.
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia. Electronic address: yknirel@gmail.com.
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457 Tianjin, China.
authors.forename: Chengqian
authors.initials: C
authors.lastname: Qian
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia.
authors.forename: Sofya N
authors.initials: SN
authors.lastname: Senchenkova
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 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: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia.
authors.forename: Alexander O
authors.initials: AO
authors.lastname: Chizhov
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia.
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Perepelov
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457 Tianjin, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
mesh_terms: D002240:Carbohydrate Sequence; D004926:Escherichia coli / Q000737:chemistry*; D005643:Fucose / Q000031:analogs & derivatives / Q000737:chemistry; D006600:Hexosephosphates / Q000737:chemistry; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D019081:O Antigens / Q000737:chemistry* / Q000302:isolation & purification; D013329:Structure-Activity Relationship
chemical_list: D006600:Hexosephosphates; D008070:Lipopolysaccharides; D019081:O Antigens; C081214:fucopyranosyl phosphate; D005643:Fucose
keywords: Bacterial polysaccharide structure; Glycosyl phosphate; O-antigen gene cluster