Functional and structural characterization of AntR, an Sb(III) responsive transcriptional repressor
- Florida International Univ. (FIU), Miami, FL (United States)
- Huazhong Agricultural Univ., Wuhan (China)
- Univ. of Georgia, Athens, GA (United States)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
The ant operon of the antimony-mining bacterium Comamonas testosterone JL40 confers resistance to Sb(III). The operon is transcriptionally regulated by the product of the first gene in the operon, antR. AntR is a member of ArsR/SmtB family of metal/metalloid-responsive repressors resistance. We purified and characterized C. testosterone AntR and demonstrated that it responds to metalloids in the order Sb(III) = methylarsenite (MAs(III) >> As(III)). The protein was crystallized, and the structure was solved at 2.1 Å resolution. The homodimeric structure of AntR adopts a classical ArsR/SmtB topology architecture. The protein has five cysteine residues, of which Cys103a from one monomer and Cys113b from the other monomer, are proposed to form one Sb(III) binding site, and Cys113a and Cys103b forming a second binding site. This is the first report of the structure and binding properties of a transcriptional repressor with high selectivity for environmental antimony.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- National Natural Science Foundation of China (NSFC); National Institutes of Health (NIH); USDOE Office of Science (SC), Basic Energy Sciences (BES); National Institute of General Medical Sciences (NIGMS); Howard Hughes Medical Institute
- Grant/Contract Number:
- AC02-05CH11231; 2016YFD0800702; 31970095; GM055425: GM136211: ES023779; W-31-109-Eng-38
- OSTI ID:
- 1842462
- Journal Information:
- Molecular Microbiology, Vol. 116, Issue 2; ISSN 0950-382X
- Publisher:
- WileyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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