title: Structural and genetic characterization of the O-antigen of Salmonella enterica O56 containing a novel derivative of 4-amino-4,6-dideoxy-D-glucose.
abstract: Based on the O-antigens (O-polysaccharides), one of the most variable cell constituents, 46 O-serogroups have been recognized in the Kauffmann-White serotyping scheme for Salmonella enterica. In this work, the structure of the O-polysaccharide and the genetic organization of the O-antigen gene cluster of S. enterica O56 were investigated. As judged by sugar and methylation analyses, along with NMR spectroscopic data, the O-polysaccharide has a linear tetrasaccharide O-unit, which consists of one residue each of d-ribofuranose, N-acetyl-d-glucosamine, N-acetyl-d-galactosamine, and a novel sugar derivative, 4-(N-acetyl-l-seryl)amino-4,6-dideoxy-d-glucose (d-Qui4NSerAc). The following structure of the O-polysaccharide was established: -->3)-beta-d-Quip4NSerAc-(1-->3)-beta-d-Ribf-(1-->4)-alpha-d-GalpNAc-(1-->3)-alpha-d-GlcpNAc-(1--> The O-antigen gene cluster of S. enterica O56 having 12 open reading frames was found between the housekeeping genes galF and gnd. A comparison with databases and using the O-antigen structure data enabled us to ascribe functions to genes for (i) synthesis of d-GalNAc and d-Qui4NSerAc, (ii) sugar transfer, and (iii) O-antigen processing, including genes for O-unit flippase (Wzx) and O-antigen polymerase (Wzy).
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation. perepel@ioc.ac.ru
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Perepelov
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Sergei D
authors.initials: SD
authors.lastname: Shevelev
authors.forename: Sof'ya N
authors.initials: SN
authors.lastname: Senchenkova
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Lu
authors.initials: L
authors.lastname: Feng
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
mesh_terms: D002240:Carbohydrate Sequence; D005944:Glucosamine / Q000031:analogs & derivatives* / Q000737:chemistry; D008969:Molecular Sequence Data; D005810:Multigene Family; D019081:O Antigens / Q000737:chemistry* / Q000235:genetics*; D019779:Salmonella enterica / Q000737:chemistry* / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: C492812:4-amino-4,6-dideoxyglucose; D019081:O Antigens; D005944:Glucosamine