The goal of this project is determination of the structure of the metal binding sites that form the inducer binding domains of transcriptional repressors that regulate plasmid-encoded bacterial resistances. In common with many drug and antibiotic resistances, the arsenical (ars) and cadmium (cad) resistance operons encode transport ATPases for the extrusion of As(III)/Sb(III) or Pb(II)/Cd(II)/Zn(II). The ArsR and CadC repressors are two small homologous metalloregulatory proteins responsible for metal-regulated gene expression of the ars and cad operons. Residues required for each inducer binding domain will be determined. In addition, in ars operons there is a second As(III)/Sb(III)-responsive repressor, ArsD, which does not exhibit homology to any known metal binding protein. ArsR and ArsD form a regulatory circuit that senses both low and high concentrations of environmental metalloid. The residues involved in As(III)/Sb(III) binding to ArsD will be determined. Finally, the copper (copA) resistance gene encodes a Cu(I)-translocating P-type ATPase. Expression of copA is regulated by copper or silver. The putative CopR regulatory protein will be identified and characterized. Our studies will define new classes of metal binding motifs. This may be more general applicability, since nearly all transport-related drug resistances are transcriptionally regulated, and the drug binding motifs of the regulatory proteins are largely unknown. Thus the repressors of the genes for these efflux pumps provide good model systems for the study of regulation of transmissible bacterial antibiotic resistances.
| Ajees, A Abdul; Yang, Jianbo; Rosen, Barry P (2011) The ArsD As(III) metallochaperone. Biometals 24:391-9 |
| Ye, Jun; He, Yanan; Skalicky, Jack et al. (2011) Resonance assignments and secondary structure prediction of the As(III) metallochaperone ArsD in solution. Biomol NMR Assign 5:109-12 |
| Yang, Jianbo; Salam, Abdul Ajees Abdul; Rosen, Barry P (2011) Genetic mapping of the interface between the ArsD metallochaperone and the ArsA ATPase. Mol Microbiol 79:872-81 |
| Yang, Jianbo; Rawat, Swati; Stemmler, Timothy L et al. (2010) Arsenic binding and transfer by the ArsD As(III) metallochaperone. Biochemistry 49:3658-66 |
| Rosen, Barry P; Tamás, Markus J (2010) Arsenic transport in prokaryotes and eukaryotic microbes. Adv Exp Med Biol 679:47-55 |
| Ye, Jun; Ajees, A Abdul; Yang, Jianbo et al. (2010) The 1.4 A crystal structure of the ArsD arsenic metallochaperone provides insights into its interaction with the ArsA ATPase. Biochemistry 49:5206-12 |
| Kandegedara, Ashoka; Thiyagarajan, Saravanamuthu; Kondapalli, Kalyan C et al. (2009) Role of bound Zn(II) in the CadC Cd(II)/Pb(II)/Zn(II)-responsive repressor. J Biol Chem 284:14958-65 |
| Qin, Jie; Lehr, Corinne R; Yuan, Chungang et al. (2009) Biotransformation of arsenic by a Yellowstone thermoacidophilic eukaryotic alga. Proc Natl Acad Sci U S A 106:5213-7 |
| Ordonez, Efren; Thiyagarajan, Saravanamuthu; Cook, Jeremy D et al. (2008) Evolution of metal(loid) binding sites in transcriptional regulators. J Biol Chem 283:25706-14 |
| Uzcategui, Nestor L; Zhou, Yao; Figarella, Katherine et al. (2008) Alteration in glycerol and metalloid permeability by a single mutation in the extracellular C-loop of Leishmania major aquaglyceroporin LmAQP1. Mol Microbiol 70:1477-86 |
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