Structure and Biosynthesis Gene Cluster of the O-Antigen of Escherichia coli O12.
Two polysaccharides were isolated from Escherichia coli O12, the major being identified as the O12-antigen and the minor as the K5-antigen. The polysaccharides were studied by sugar analysis, Smith degradation, and one- and two-dimensional (1)H and (13)C NMR spectroscopy. As a result, the following structure of the O12-polysaccharide was elucidated, which, to our knowledge, has not been hitherto found in bacterial carbohydrates: →2)-β-d-Glcp-(1→6)-α-d-GlcpNAc-(1→3)-α-l-FucpNAc-(1→3)-β-d-GlcpNAc-(1→. The →4)-β-d-GlcpA-(1→4)-α-d-GlcpNAc-(1→ structure established for the K5-polysaccharide (heparosan) is previously known. Functions of genes in the O-antigen biosynthesis gene cluster of E. coli O12 were assigned by comparison with sequences in the available databases and found to be consistent with the O12-polysaccharide structure.
Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 119991, Russia. yknirel@gmail.com.
S N
SN
Senchenkova
Yuanyuan
Y
Zhang
A V
AV
Perepelov
Xi
X
Guo
A S
AS
Shashkov
Bin
B
Liu
Yu A
YA
Knirel
D002240:Carbohydrate Sequence; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D062126:Databases, Chemical; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides / Q000737:chemistry / Q000302:isolation & purification; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D019081:O Antigens / Q000737:chemistry* / Q000235:genetics*; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification; D066244:Proton Magnetic Resonance Spectroscopy
D029968:Escherichia coli Proteins; D008070:Lipopolysaccharides; D019081:O Antigens; D011134:Polysaccharides