Interaction of the FimB Integrase with the fimS Invertible DNA Element in Escherichia coli In Vivo and In Vitro

AUTOR(ES)

Burns, Lesley S.

FONTE

American Society for Microbiology

RESUMO

The FimB protein is a site-specific recombinase that inverts the fimS genetic switch in Escherichia coli. Based on amino acid sequence analysis alone, FimB has been assigned to the integrase family of tyrosine recombinases. We show that amino acid substitutions at positions R47, H141, R144, and Y176, corresponding to highly conserved members of the catalytic motif of integrase proteins, render FimB incapable of inverting the fimS element in vivo. The arginine substitutions reduced the ability of FimB to bind to fimS in vivo or in vitro, while the substitution R144Q resulted in a protein unable to bind independently to the half sites located at the left end of fimS in phase-on bacteria. These data confirm that FimB is an integrase and suggest that residue R144 has a role in binding to a specific component of the fim switch.

Documentos Relacionados

• Roles of fimB and fimE in site-specific DNA inversion associated with phase variation of type 1 fimbriae in Escherichia coli.
• Promoter-specific repression of fimB expression by the Escherichia coli nucleoid-associated protein H-NS.
• Type 1 Fimbriation and Phase Switching in a Natural Escherichia coli fimB Null Strain, Nissle 1917
• Integrated regulatory responses of fimB to N-acetylneuraminic (sialic) acid and GlcNAc in Escherichia coli K-12
• Interaction of Escherichia coli dnaB and dnaC(D) gene products in vitro.