Mechanisms of metalloregulation of an anion-translocating ATPase.
The ars (arsenical resistance) operon cloned from R-factor R773 has five genes that encode two repressor proteins, ArsR and ArsD, and three structural proteins, ArsA, ArsB, and ArsC. The ArsA and ArsB proteins form a membrane-bound pump that functions as an oxyanion-translocating ATPase. The substrates of the pump are the oxyanions arsenite or antimonite. The ArsC protein is an arsenate reductase that reduces arsenate to arsenite, which is subsequently pumped out of the cell. This review deals with the mechanism of transcriptional regulation by the ArsR repressor and allosteric regulation of the ArsA protein, the catalytic subunit of the pump. The chemical nature of the inducer plays an important role in regulation. In solution arsenite or antimonite exist as oxyanions and reacts with the cysteines in proteins. In both transcriptional regulation by the ArsR repressor and allosteric regulation of the ArsA ATPase, the ability of As(III) and Sb(III) to interact with the cysteines of the proteins, involves their action as effector.
Rosen
B P
BP
Department of Biochemistry, Wayne State University, School of Medicine, Detroit, Michigan 48201, USA.
Bhattacharjee
H
H
Shi
W
W
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D001152:Arsenicals / Q000494:pharmacology*; D053501:Arsenite Transporting ATPases; D016384:Consensus Sequence; D017124:Conserved Sequence; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D016623:Ion Pumps; D008565:Membrane Proteins / Q000378:metabolism; D008670:Metals / Q000494:pharmacology*; D008961:Models, Structural; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes; D009876:Operon; D011487:Protein Conformation
D001152:Arsenicals; D016623:Ion Pumps; D008565:Membrane Proteins; D008670:Metals; D009097:Multienzyme Complexes; D000251:Adenosine Triphosphatases; D053501:Arsenite Transporting ATPases