Regulatory Interactions among adhesin gene systems of uropathogenic Escherichia coli.
Uropathogenic Escherichia coli strain J96 carries multiple determinants for fimbrial adhesins. The regulatory protein PapB of P fimbriae has previously been implicated in potential coregulatory events. The focB gene of the F1C fimbria determinant is highly homologous to papB; the translated sequences share 81% identity. In this study we investigated the role of PapB and FocB in regulation of the F1C fimbriae. By using gel mobility shift assays, we showed that FocB binds to sequences in both the pap and foc operons in a somewhat different manner than PapB. The results of both in vitro cross-linking and in vivo oligomerization tests indicated that FocB could function in an oligomeric fashion. Furthermore, our results suggest that PapB and FocB can form heterodimers and that these complexes can repress expression of the foc operon. The effect of FocB on expression of type 1 fimbriae was also tested. Taken together, the results that we present expand our knowledge about a regulatory network for different adhesin gene systems in uropathogenic E. coli and suggest a hierarchy for expression of the fimbrial adhesins.
Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå University, S-90187 Umeå, Sweden.
Stina
S
Lindberg
Yan
Y
Xia
Berit
B
Sondén
Mikael
M
Göransson
Jörg
J
Hacker
Bernt Eric
BE
Uhlin
D018829:Adhesins, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D036781:Fimbriae Proteins / Q000096:biosynthesis* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000378:metabolism*
D018829:Adhesins, Bacterial; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D014157:Transcription Factors; C116245:atpD protein, E coli; D036781:Fimbriae Proteins