Site-directed mutagenesis reveals putative substrate binding residues in the Escherichia coli RND efflux pump AcrB.
The Escherichia coli multidrug efflux pump protein AcrB has recently been cocrystallized with various substrates, suggesting that there is a phenylalanine-rich binding site around F178 and F615. We found that F610A was the point mutation that had the most significant impact on substrate MICs, while other targeted mutations, including conversion of phenylalanines 136, 178, 615, 617, and 628 to alanine, had smaller and more variable effects.
Center for Infectious Diseases and Travel Medicine, University Hospital, Department of Medicine, Albert Ludwigs University, Freiburg, Germany. juergen@bohnert.name
Jürgen A
JA
Bohnert
Sabine
S
Schuster
Markus A
MA
Seeger
Eva
E
Fähnrich
Klaas M
KM
Pos
Winfried V
WV
Kern
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001665:Binding Sites; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D010649:Phenylalanine / Q000235:genetics; D017354:Point Mutation
D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D010649:Phenylalanine; C083496:AcrB protein, E coli