PHENYLMERCURY TRANSPORT MEDIATED BY merT-merP GENES OF PSEUDOMONAS K-62 PLASMID pMR26

Abstract

The merB-merA-deleted plasmid pMRD141 which contains the intact merT-merP genes of pMRA17 conferred bacterial hypersensitivity not only to Hg²⁺ but also to C₆H₅Hg⁺. The bacterium with pMRD141 took up significantly more C₆H₅Hg⁺ than its isogenic strain with the cloning vector BluescriptII. The hypersensitivity to C₆H₅Hg⁺ seems to be based on hyperaccumulation of toxic C₆H₅Hg⁺ in the absence of detoxifying enzymes encoded by merB and merA. Our results show that bacterial transport of C₆H₅Hg⁺ into the cytoplasm is regulated by merT-merP genes.