| Literature DB >> 11166990 |
K Saito1, S Eda, H Maseda, T Nakae.
Abstract
To elucidate the molecular mechanism by which the MexR repressor regulates expression of the MexAB-OprM efflux pump, we investigated MexR and the mexR-mexA intergenic DNA (mexOP) interaction, and transcription of the mexA-lacZ reporter gene containing different lengths of mexOP. Homogeneously purified MexR bound specifically to mexOP proximal to mexR. The mexOP-lacZ fusion gene lacking the region immediately proximal to mexR showed minimum enzyme activity, thereby suggesting that a promoter element is located between mexR and the MexR-binding sites. These observations explain the mechanism of self-regulation of mexR expression as well as low and elevated expression of MexAB-OprM in the wild-type strain and nalB-type mutant, respectively, of Pseudomonas aeruginosa.Entities:
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Year: 2001 PMID： 11166990 DOI： 10.1111/j.1574-6968.2001.tb10492.x
Source DB: PubMed Journal: FEMS Microbiol Lett ISSN： 0378-1097 Impact factor: 2.742