caa a22 4500 463208501 CHVBK 20180405153133.0 cr unu---uuuuu 170326e20071201xx s 000 0 eng 10.1007/s10863-007-9113-y doi (NATIONALLICENCE)springer-10.1007/s10863-007-9113-y ArsD: an As(III) metallochaperone for the ArsAB As(III)-translocating ATPase [Elektronische Daten] [Yung-Feng Lin, Jianbo Yang, Barry Rosen] The toxic metalloid arsenic is widely disseminated in the environment and causes a variety of health and environment problems. As an adaptation to arsenic-contaminated environments, organisms have developed resistance systems. Many ars operons contain only three genes, arsRBC. Five gene ars operons have two additional genes, arsD and arsA, and these two genes are usually adjacent to each other. ArsA from Escherichia coli plasmid R773 is an ATPase that is the catalytic subunit of the ArsAB As(III) extrusion pump. ArsD was recently identified as an arsenic chaperone to the ArsAB pump, transferring the trivalent metalloids As(III) and Sb(III) to the ArsA subunit of the pump. This increases the affinity of ArsA for As(III), resulting in increased rates if extrusion and resistance to environmentally relevant concentrations of arsenite. ArsD is a homodimer with three vicinal cysteine pairs, Cys12-Cys13, Cys112-Cys113 and Cys119-Cys120, in each subunit. Each vicinal pair binds one As(III) or Sb(III). ArsD mutants with alanines substituting for Cys112, Cys113, Cys119 or Cys120, individually or in pairs or truncations lacking the vicinal pairs, retained ability to interact with ArsA, to activate its ATPase activity. Cells expressing these mutants retained ArsD-enhanced As(III) efflux and resistance. In contrast, mutants with substitutions of conserved Cys12, Cys13 or Cys18, individually or in pairs, were unable to activate ArsA or to enhance the activity of the ArsAB pump. It is proposed that ArsD residues Cys12, Cys13 and Cys18, but not Cys112, Cys113, Cys119 or Cys120, are required for delivery of As(III) to and activation of the ArsAB pump. Springer Science+Business Media, LLC, 2007 Arsenic nationallicence Arsenite nationallicence Antimony nationallicence Resistance pump nationallicence ArsD nationallicence ArsA nationallicence Lin Yung-Feng Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, 48201, Detroit, MI, USA aut Yang Jianbo Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, 48201, Detroit, MI, USA aut Rosen Barry Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, 48201, Detroit, MI, USA aut Journal of Bioenergetics and Biomembranes Springer US; http://www.springer-ny.com 39/5-6(2007-12-01), 453-458 0145-479X 39:5-6<453 2007 39 10863 https://doi.org/10.1007/s10863-007-9113-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10863-007-9113-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lin Yung-Feng Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, 48201, Detroit, MI, USA aut NATIONALLICENCE 700 1- Yang Jianbo Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, 48201, Detroit, MI, USA aut NATIONALLICENCE 700 1- Rosen Barry Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, 48201, Detroit, MI, USA aut NATIONALLICENCE 773 0- Journal of Bioenergetics and Biomembranes Springer US; http://www.springer-ny.com 39/5-6(2007-12-01), 453-458 0145-479X 39:5-6<453 2007 39 10863 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer