dbCAN-PUL

PUL ID	PUL0057
PubMed	29787897, Carbohydr Res. 2018 Jul 15;464:8-11. doi: 10.1016/j.carres.2018.05.001. Epub 2018 May 7.
Characterization method	NMR,sequence homology analysis
Genomic accession number	AB811624
Nucelotide position range	1-11989
Substrate	O-antigen
Loci	rmlB-rmlD-rmlA-fdtC-wzx-wegP-rmlC-wzy-wegQ-wegR
Species	Escherichia coli/562
Degradation or Biosynthesis	biosynthesis

PUL ID	PUL0057
PubMed	29787897, Carbohydr Res. 2018 Jul 15;464:8-11. doi: 10.1016/j.carres.2018.05.001. Epub 2018 May 7.
Title	Structural and genetic relatedness of the O-antigens of Escherichia coli O50 and O2.
Author	Yang B, Senchenkova SN, Naumenko OI, Shashkov AS, Liu B, Perepelov AV, Knirel YA
Abstract	An O-specific polysaccharide (O-antigen) was isolated by mild acid degradation of the lipopolysaccharide of Escherichia coli O50 followed by gel chromatography on Sephadex G-50. The following structure of the tetrasaccharide repeat was established by sugar analysis and 1D and 2D (1)H and (13)C NMR spectroscopy: -->3)-alpha-l-Rhap-(1 --> 2)-alpha-l-Rhap-(1 --> 3)-beta-l-Rhap-(1 --> 4)-beta-d-GlcpNAc-(1--> The linear O50 polysaccharide has the same structure as the main chain of the branched O polysaccharide of E. coli O2 studied earlier [Jansson et al., Carbohydr. Res. 161 (1987) 273-279], which differs in the presence of a side-chain alpha-d-Fucp3NAc residue. In spite of the difference between the O-polysaccharides, the corresponding genes in the O2- and O50-antigen gene cluster are 99-100% identical. The genetic basis for the lack of d-Fucp3NAc from the O50 polysaccharide is evidently a point mutation in the aminotransferase gene fdtB of the d-Fucp3NAc synthesis pathway resulting in a single amino acid change from histidine in O2 to arginine in O50.