title: O antigen of FranconibacterpulverisG3872 (O1) is a 4-deoxy-d-arabino-hexose-containing polysaccharide synthesized by the ABC-transporter-dependent pathway.
abstract: Franconibacter (Enterobacter, Cronobacter) pulveris bacteria share several typical characteristics with, and hence pose a challenge for the detection of, Cronobacter sakazakii, an emerging opportunistic pathogen, which can cause severe infections in neonates. A structurally variable O-specific polysaccharide (OPS) called O antigen provides the major basis for the typing of Gram-negative bacteria. We investigated the structure and genetics of the O antigen of F. pulveris G3872 (designated O1). An OPS was isolated by mild alkaline degradation of the LPS, whereas the same polysaccharide and its oligosaccharide fragments were obtained by mild acid degradation. Studies by sugar analysis and NMR spectroscopy showed that the OPS contained d-ribose, l-rhamnose (l-Rha) and a rarely occurring monosaccharide 4-deoxy-d-arabino-hexose, and the OPS structure was established. The O-antigen gene cluster of F. pulveris G3872 between JUMPStart and gnd genes includes putative genes for glycosyltransferases, ATP-binding cassette (ABC)-transporter genes wzm and wzt, and genes for the synthesis of l-Rha, but no genes for the synthesis of 4-deoxy-d-arabino-hexose. A mutation test with the wzm gene confirmed that the OPS is synthesized and exported by the ABC-transporter-dependent pathway. A trifunctional transferase was suggested to catalyse formation of two glycosidic linkages and add a methyl group to the non-reducing end of the OPS to terminate the chain elongation. A carbohydrate-binding module that presumably recognizes the terminal methyl-modified monosaccharide was found at the C-terminus of Wzt. Primers specific for F. pulveris G3872 were designed based on the wzm gene, which has potential to be used for identification and detection of the O1 serogroup.
authors.affiliation: TEDA School of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457 Tianjin, China.|Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071 Tianjin, 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, Russia.
authors.forename: Nikolay P
authors.initials: NP
authors.lastname: Arbatsky
authors.affiliation: TEDA School of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457 Tianjin, China.|Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071 Tianjin, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Xu
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: TEDA School of Biological Sciences and Biotechnology, Nankai University, TEDA, 300457 Tianjin, China.|Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071 Tianjin, 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, Russia.
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D001483:Base Sequence; D044083:Cronobacter sakazakii / Q000145:classification / Q000276:immunology; D004755:Enterobacteriaceae / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D019081:O Antigens / Q000737:chemistry* / Q000235:genetics* / Q000276:immunology; D009844:Oligosaccharides / Q000737:chemistry*; D017422:Sequence Analysis, DNA
chemical_list: D018528:ATP-Binding Cassette Transporters; D019081:O Antigens; D009844:Oligosaccharides