Soft metal thiol chemistry is not involved in the transport of arsenite by the Ars pump.
The single cysteine in the ArsB protein subunit of the arsenite resistance pump was changed to serine and alanine residues. Resistance in cells expressing the two mutant arsB genes was the same as in the wild type, and the serine substitution had no effect on the arsenite transport properties. These results eliminate possible thiol chemistry in translocation. Thus, the pump uses soft metal chemistry for metalloactivation and nonmetal chemistry for oxyanion transport.
Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Y
Chen
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S
Dey
B P
BP
Rosen
D000251:Adenosine Triphosphatases / Q000502:physiology*; D053501:Arsenite Transporting ATPases; D018053:Arsenites / Q000493:pharmacokinetics*; D001483:Base Sequence; D001692:Biological Transport; D003545:Cysteine / Q000502:physiology; D016623:Ion Pumps; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D013329:Structure-Activity Relationship
D018053:Arsenites; D016623:Ion Pumps; D009097:Multienzyme Complexes; D000251:Adenosine Triphosphatases; D053501:Arsenite Transporting ATPases; D003545:Cysteine; C015001:arsenite