GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:10417177

From GONUTS
Jump to: navigation, search
Citation

Lindenthal, C and Elsinghorst, EA (1999) Identification of a glycoprotein produced by enterotoxigenic Escherichia coli. Infect. Immun. 67:4084-91

Abstract

Enterotoxigenic Escherichia coli (ETEC) strain H10407 is capable of invading epithelial cell lines derived from the human ileocecum and colon in vitro. Two separate chromosomally encoded invasion loci (tia and tib) have been cloned from this strain. These loci direct nonadherent and noninvasive laboratory strains of E. coli to adhere to and invade cultured human intestinal epithelial cells. The tib locus directs the synthesis of TibA, a 104-kDa outer membrane protein that is directly correlated with the adherence and invasion phenotypes. TibA is synthesized as a 100-kDa precursor (preTibA) that must be modified for biological activity. Outer membranes of recombinant E. coli expressing TibA or preTibA were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted to nitrocellulose. The presence of glycoproteins was detected by oxidization of carbohydrates with periodate and labeling with hydrazide-conjugated digoxigenin. Only TibA could be detected as a glycoprotein. Complementation experiments with tib deletion mutants of ETEC strain H10407 demonstrate that the TibA glycoprotein is expressed in H10407, that the entire tib locus is required for TibA synthesis, and that TibA is the only glycoprotein produced by H10407. Protease treatment of intact H10407 cells removes the carbohydrates on TibA, suggesting that they are surface exposed. TibA shows homology with AIDA-I from diffuse-adhering E. coli and with pertactin precursor from Bordetella pertussis. Both pertactin and AIDA-I are members of the autotransporter family of outer membrane proteins and are afimbrial adhesins that play an important role in the virulence of these organisms. Analysis of the predicted TibA amino acid sequence indicates that TibA is also an autotransporter. Analysis of the tib locus DNA sequence revealed an open reading frame with similarity to RfaQ, a glycosyltransferase. The product of this tib locus open reading frame is proposed to be responsible for TibA modification. These results suggest that TibA glycoprotein acts as an adhesin that may participate in the disease process.

Links

PubMed PMC96707

Keywords

Amino Acid Sequence; Bacterial Outer Membrane Proteins/analysis; Bacterial Outer Membrane Proteins/chemistry; Bacterial Outer Membrane Proteins/genetics; Chromosome Mapping; DNA, Bacterial/chemistry; Escherichia coli/chemistry; Escherichia coli/pathogenicity; Glycoproteins/analysis; Glycoproteins/chemistry; Glycoproteins/genetics; Molecular Sequence Data; Protein Structure, Secondary; Virulence

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

ECOH1:TIBA

GO:0045203: integral to cell outer membrane

ECO:0000314:

C

Fig 1B&C + Fig 2B

complete
CACAO 6178

ECOH1:TIBA

part_of

GO:0045203: integral component of cell outer membrane

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.