Mutations in the central cavity and periplasmic domain affect efflux activity of the resistance-nodulation-division pump EmhB from Pseudomonas fluorescens cLP6a.

ABSTRACT: The EmhABC efflux system in Pseudomonas fluorescens cLP6a is homologous to the multidrug and solvent efflux systems belonging to the resistance-nodulation-division (RND) family and is responsible for polycyclic aromatic hydrocarbon transport, antibiotic resistance, and toluene efflux. To gain a better understanding of substrate transport in RND efflux pumps, the EmhB pump was subjected to mutational analysis. Mutagenesis of amino acids within the central cavity of the predicted three-dimensional structure of EmhB showed selective activity towards antibiotic substrates. An A384P/A385Y double mutant showed increased susceptibility toward rhodamine 6G compared to the wild type, and F386A and N99A single mutants showed increased susceptibility to dequalinium compared to the wild type. As well,

SUBMITTER: Hearn EM 

PROVIDER: S-EPMC1317607 | biostudies-literature | 2006 Jan

REPOSITORIES: biostudies-literature