title: Structure and gene cluster of the O-antigen of Enterobacter cloacae G3421.
abstract: The O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G3421 and studied by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy. In addition, partial solvolysis with anhydrous trifluoroacetic acid was applied, which cleaved selectively the α-l-rhamnopyranosidic linkages. The following structure of the branched hexasaccharide repeating unit was established. The O-polysaccharide studied shares the β-l-Rhap-(1→4)-α-l-Rhap-(1→2)-α-l-Rhap trisaccharide fragment with the O-polysaccharide of Shigella boydii type 18. The O-antigen gene cluster of E. cloacae G3421 was sequenced. Functions of genes in the cluster, including those for glycosyltransferases, were tentatively assigned by a comparison with sequences in the available databases and found to be consistent with the O-polysaccharide structure.
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation. Electronic address: perepel@ioc.ac.ru.
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Perepelov
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Filatov
authors.affiliation: TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, China; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.affiliation: TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, China; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
mesh_terms: D002240:Carbohydrate Sequence; D016972:Enterobacter cloacae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D005810:Multigene Family; D019906:Nuclear Magnetic Resonance, Biomolecular; D019081:O Antigens / Q000737:chemistry* / Q000235:genetics*; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D019081:O Antigens; D011135:Polysaccharides, Bacterial
keywords: Bacterial polysaccharide structure; Enterobacter cloacae; Lipopolysaccharide; O-antigen gene cluster; Solvolytic cleavage