Horizontal gene transfer of the Escherichia coli pap and prs pili operons as a mechanism for the development of tissue-specific adhesive properties.
Escherichia coli strains bind to Gal alpha 1-4Gal-containing glycolipids via P pili-associated G-adhesins. Three functional classes of adhesins with different binding specificities are encoded by conserved G-alleles. We suggest that the Class I papG-allele of strain J96 is a novel acquisition possibly introduced via horizontal gene transfer into one of the two P pili gene clusters carried by this strain. Closely related strains in the ECOR collection of natural E. coli isolates carry either a Class II or a Class III G-adhesin. Data indicate that genetic exchanges involving either entire pap or prs gene clusters or individual pap/prs genes have occurred. We propose that the retention and spread of pap/prs DNA among E. coli is the result of selection pressure exerted by mammalian intestinal isoreceptors.
Department of Microbiology, University of Umeå, Sweden.
B I
BI
Marklund
J M
JM
Tennent
E
E
Garcia
A
A
Hamers
M
M
Båga
F
F
Lindberg
W
W
Gaastra
S
S
Normark
D018830:Adhesins, Escherichia coli; D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D005075:Biological Evolution; D002240:Carbohydrate Sequence; D004269:DNA, Bacterial; D004926:Escherichia coli / Q000235:genetics*; D010861:Fimbriae, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D009876:Operon; D015183:Restriction Mapping; D017385:Sequence Homology; D014162:Transfection
D018830:Adhesins, Escherichia coli; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial