Mutations affecting DNA-binding activity of the MexR repressor of mexR-mexA-mexB-oprM operon expression.
We have isolated 25 MexR mutants that retained their dimerizing ability but were unable to bind mexOP DNA. Surprisingly, 20 mutations were located in the hydrophobic core region at alpha4, W1, alpha2, alpha3, and beta2, and only 3 were in positively charged residues. These results verified that DNA binding is mediated by distinct regions of MexR and showed the importance of the hydrophobic core region of the DNA-binding domain.
Saito
Kohjiro
K
Department of Molecular Life Science, Tokai University School of Medicine, Isehara 259-1193, Japan.
Akama
Hiroyuki
H
Yoshihara
Eisaku
E
Nakae
Taiji
T
D001398:Aztreonam / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism*; D018432:Drug Resistance, Multiple; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D009154:Mutation; D015242:Ofloxacin / Q000494:pharmacology; D009876:Operon; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D026901:Membrane Transport Proteins; C118598:MexA protein, Pseudomonas aeruginosa; C118597:MexB protein, Pseudomonas aeruginosa; C423620:MexR protein, Pseudomonas aeruginosa; C402263:OprM protein, Pseudomonas aeruginosa; D012097:Repressor Proteins; D015242:Ofloxacin; D001398:Aztreonam