Structure of O-Antigen and Functional Characterization of O-Antigen Gene Cluster of Salmonella enterica O47 Containing Ribitol Phosphate and 2‑Acetimidoylamino-2,6-dideoxy-L-galactose

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A. V. Perepelov^1*, B. Liu^2,3, S. N. Senchenkova¹, A. S. Shashkov¹, L. Feng^2,3, L. Wang^2,3, and Y. A. Knirel¹

¹Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky pr. 47, 119991 Moscow, Russia; fax: (495) 137-6148; E-mail: perepel@ioc.ac.ru

²TEDA School of Biological Sciences and Biotechnology and ³Tianjin Key Laboratory for Microbial Functional Genomics, TEDA College, Nankai University, 23 HongDa Street, TEDA, Tianjin 300457, P. R. China

^* To whom correspondence should be addressed.

Received August 21, 2008; Revision received October 16, 2008

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An O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Salmonella enterica O47 and studied by sugar analysis along with one- and two-dimensional ¹H- and ¹³C-NMR spectroscopy. The following structure of the linear ribitol phosphate-containing repeating unit of the O-polysaccharide was established:

→2)-D-Ribitol-5-P-(O→6)-α-D-Galp-(1→3)-α-L-FucpNAm-(1→3)-β-D-GlcpNAc-(1→,

where FucNAm stands for 2-acetimidoylamino-2,6-dideoxy-L-galactose. About 10% of Gal is O‑acetylated at position 4 and another minor O-acetyl group is present at an undetermined position. Functions of the S. enterica O47 antigen biosynthetic genes were tentatively assigned by comparison with gene databases and found to be in agreement with the O-polysaccharide structure. A comparison of the O-antigen gene clusters of S. enterica O47 and E. coli O145 suggested their close evolutionary relationship.

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KEY WORDS: Salmonella enterica, lipopolysaccharide, bacterial polysaccharide structure, acetimidoyl group, ribitol phosphate, O-antigen gene cluster

DOI: 10.1134/S0006297909040099

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