Structural and genetic characterization of the O-antigen of Escherichia coli O161 containing a derivative of a higher acidic diamino sugar, legionaminic acid.
The O-antigen is an essential component of lipopolysaccharide on the surface of Gram-negative bacteria and plays an important role in its pathogenicity. Composition and structure of the O-antigens of Escherichia coli are highly diverse mainly due to genetic variations in the O-antigen gene cluster. In this work, the chemical structure and the gene cluster of the O-antigen of E. coli O161 were studied. Chemical degradations, sugar analyses, and NMR spectroscopy showed that the O161 antigen possesses a trisaccharide O-repeating unit containing a 5-N-acetyl-7-N-(d-alanyl) derivative of 5,7-diamino-3,5,7,9-tetradeoxy-d-glycero-d-galacto-non-2-ulosonic (legionaminic) acid (Leg5Ac7Ala) and having the following structure: The O-antigen gene cluster of E. coli O161 was sequenced. In addition to the genes encoding sugar transferases, O-repeating unit flippase (Wzx) and O-antigen polymerase (Wzy), the genes involved in the biosynthesis of a legionaminic acid derivative were identified based on database similarities.
TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin, PR China.
Xiaomin
X
Li
Andrei V
AV
Perepelov
Quan
Q
Wang
Sof'ya N
SN
Senchenkova
Bin
B
Liu
Sergei D
SD
Shevelev
Xi
X
Guo
Alexander S
AS
Shashkov
Wei
W
Chen
Lei
L
Wang
Yuriy A
YA
Knirel
D002240:Carbohydrate Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D019081:O Antigens / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012794:Sialic Acids / Q000737:chemistry*
C110570:5,7-diacetamido-8-O-acetyl-3,5,7,9-tetradeoxy-glycero-talo-nonulosonic acid; D019081:O Antigens; D012794:Sialic Acids