Biomaterial Database

Deletion of the Escherichia coli O14:K7 O antigen gene cluster. 2004

Slade O Jensen, and Peter R Reeves

School of Molecular and Microbial Sciences, University of Sydney, New South Wales, Australia.

Escherichia coli O14:K7 is a rough strain, lacking a typical O antigen, in which the enterobacterial common antigen is attached to the lipopolysaccharide core. The rough phenotype was previously mapped to the O antigen gene cluster; however, the nature of the nonfunctional locus was not defined. In this study, we have shown that the O antigen gene cluster of an O14:K7 type strain (Su4411/41) was most likely deleted via homologous recombination between the GDP-mannose pathway genes (manB and manC) of the colanic acid and O antigen gene clusters. A similar recombination event has previously been inferred for the deletion of E. coli Sonnei chromosomal O antigen genes. Therefore, recombination between the GDP-mannose pathway genes provides a convenient mechanism for the deletion of O antigen genes, which may occur if the typical O antigen becomes redundant.

UI	MeSH Term	Description	Entries
D008358	Mannose	A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)	D-Mannose,Mannopyranose,Mannopyranoside,D Mannose
D011134	Polysaccharides	Long chain polymeric CARBOHYDRATES composed of MONOSACCHARIDES linked by glycosidic bonds.	Glycan,Glycans,Polysaccharide
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D006155	Guanosine Diphosphate Mannose	A nucleoside diphosphate sugar which can be converted to the deoxy sugar GDPfucose, which provides fucose for lipopolysaccharides of bacterial cell walls. Also acts as mannose donor for glycolipid synthesis.	GDP Mannose,Guanosine Diphosphomannose,Guanosine Pyrophosphate Mannose,Diphosphate Mannose, Guanosine,Diphosphomannose, Guanosine,Mannose, GDP,Mannose, Guanosine Diphosphate,Mannose, Guanosine Pyrophosphate,Pyrophosphate Mannose, Guanosine
D017353	Gene Deletion	A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.	Deletion, Gene,Deletions, Gene,Gene Deletions
D019081	O Antigens	The lipopolysaccharide-protein somatic antigens, usually from gram-negative bacteria, important in the serological classification of enteric bacilli. The O-specific chains determine the specificity of the O antigens of a given serotype. O antigens are the immunodominant part of the lipopolysaccharide molecule in the intact bacterial cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	O-Antigen,O-Specific Polysaccharides,O Antigen,O Antigen, Bacterial,O-Antigens,O-Specific Polysaccharide,Antigen, Bacterial O,Antigen, O,Antigens, O,Bacterial O Antigen,O Specific Polysaccharide,O Specific Polysaccharides,Polysaccharide, O-Specific,Polysaccharides, O-Specific