6UVU

Crystal structure of the AntR antimony-specific transcriptional repressor

Summary for 6UVU

• Entry DOI: 10.2210/pdb6uvu/pdb
• Descriptor: ArsR family transcriptional regulator (2 entities in total)
• Functional Keywords: arsr, arsenic/antimony binding, transcriptional repressor, transcription
• Biological source: Comamonas testosteroni
• Total number of polymer chains: 2
• Total formula weight: 27069.64

Authors

Thiruselvam, V.,Banumathi, S.,Palani, K.,Manohar, R.,Rosen, B.P. (deposition date: 2019-11-04, release date: 2020-11-04, Last modification date: 2023-10-11)

Primary citation

Viswanathan, T.,Chen, J.,Wu, M.,An, L.,Kandavelu, P.,Sankaran, B.,Radhakrishnan, M.,Li, M.,Rosen, B.P.
Functional and structural characterization of AntR, an Sb(III) responsive transcriptional repressor.
Mol.Microbiol., 116:427-437, 2021

PubMed Abstract: 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 Cys103 from one monomer and Cys113 from the other monomer, are proposed to form one Sb(III) binding site, and Cys113 and Cys103 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.

PubMed: 33786926
DOI: 10.1111/mmi.14721

Experimental method

X-RAY DIFFRACTION (2.1 Å)