Perepelov A V, Wang Quan, Senchenkova S N, Shevelev S D, Shashkov A S, Feng Lu, Knirel Y A, Wang Lei
Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 119991, Russia.
Biochemistry (Mosc). 2008 Apr;73(4):406-10. doi: 10.1134/s0006297908040044.
An O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of enteropathogenic Escherichia coli O49 and studied by sugar analysis along with one- and two-dimensional 1H- and 13C-NMR spectroscopy. The following structure of the linear tetrasaccharide repeating unit of the O-polysaccharide was established: [formula], where D-Qui4N(S3HOBut) stands for 4,6-dideoxy-4-[(S)-3-hydroxybutanoylamino]-D-glucose and O-acetylation of GlcNAc is partial (~30%). To our knowledge, no N-(3-hydroxybutanoyl) derivative of Qui4N has been hitherto found in bacterial polysaccharides. Gene functions of the O-antigen gene cluster of E. coli O49 were assigned by bioinformatics analysis and found to correspond to the O-polysaccharide structure. Two new genes were revealed and suggested to be responsible for synthesis and transfer of the 3-hydroxybutanoyl group.
