Plasmid-encoded resistance to arsenic and antimony.
Resistance determinants to the toxic oxyanionic salts of arsenic and antimony are found on plasmids of both gram-negative and gram-positive organisms. In most cases these provide resistance to both the oxyanions of +III oxidation state, antimonite and arsenite, and the +V oxidation state, arsenate. In both gram-positive and -negative bacteria, resistance is correlated with efflux of the anions from cells. The determinant from the plasmid R773, isolated from a gram-negative organism, has been studied in detail. It encodes an oxyanion-translocating ATPase with three subunits, a catalytic subunit, the ArsA protein, a membrane subunit, the ArsB subunit, and a specificity factor, the ArsC protein. The first two form a membrane-bound complex with arsenite-stimulated ATPase activity. The determinants from gram-positive bacteria have only the arsB and arsC genes and encode an efflux system without the participation of an ArsA homologue.
Kaur
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Department of Biochemistry, Wayne State University, School of Medicine, Detroit, Michigan 48201.
Rosen
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BP
D000251:Adenosine Triphosphatases / Q000235:genetics; D000965:Antimony / Q000494:pharmacology*; D001151:Arsenic / Q000494:pharmacology*; D053501:Arsenite Transporting ATPases; D001419:Bacteria / Q000187:drug effects / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics*; D016623:Ion Pumps; D009097:Multienzyme Complexes; D009876:Operon; D011815:R Factors
D016623:Ion Pumps; D009097:Multienzyme Complexes; D000965:Antimony; D000251:Adenosine Triphosphatases; D053501:Arsenite Transporting ATPases; D001151:Arsenic