Lack of involvement of merT and merP in methylmercury transport in mercury resistant Pseudomonas K-62.
To clarify whether the merT and merP genes play a role in the transport of methylmercury, we constructed a deletion plasmid, pMRD141 which lacked the genes conferring the organomercurial lyase and the mercuric reductase from plasmid, pMRA17 containing the entire broad-spectrum mercury resistance determinants of the 26 kb-plasmid from Pseudomonas K-62. Plasmid, pMRD141 showed hypersensitivity to Hg2+ but still expressed a normal sensitivity to methylmercury. The mercury-induced hypersensitive cells carrying pMRD141 took up appreciably more 203Hg2+ than the induced resistant cells with pMRA17 and the sensitive cells with cloning vector, Bluescript II SK(+) but no difference in the uptake of CH3(203)Hg2+ among these three strains was found. These results suggested that the merT and merP are only involved in the Hg2+ transport but do not participate in the transport of methylmercury.
Kiyono
M
M
Faculty of Pharmaceutical Sciences, Setsunan University, Osaka, Japan.
Omura
T
T
Fujimori
H
H
Pan-Hou
H
H
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins; D004305:Dose-Response Relationship, Drug; D004352:Drug Resistance, Microbial / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008628:Mercury / Q000494:pharmacology*; D008767:Methylmercury Compounds / Q000378:metabolism*; D011506:Proteins; D011549:Pseudomonas / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D027682:Cation Transport Proteins; D008565:Membrane Proteins; C086060:MerP protein, Bacteria; D008767:Methylmercury Compounds; D011506:Proteins; C094115:mercury transport protein, bacterial; D008628:Mercury