6j0e

Structures of two ArsR As(III)-responsive repressors: implications for the mechanism of derepression

spinqualitylabelsall models 6j0e, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6j0e is a 2 chain structure with sequence from Corynebacterium glutamicum ATCC 13032. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.6Å Ligands: ARS, MPD Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A5H1ZR36_CORGL Publication Abstract from PubMed ArsR As(III)-responsive transcriptional repressors, members of the ArsR/SmtB family of metalloregulatory proteins, have been characterized biochemically but, to date, no As(III)-bound structure has been solved. Here we report two crystal structures of ArsR repressors from Acidithiobacillus ferrooxidans (AfArsR) and Corynebacterium glutamicum (CgArsR) in the As(III)-bound form. AfArsR crystallized in P21 space group and diffracted up to 1.86A. CgArsR crystallized in P212121 and diffracted up to 1.6A. AfArsR showed one As(III) bound in one subunit of the homodimer, while the CgArsR structure showed two As(III) bound with S3 coordination, one in each monomer. Previous studies indicated that in AfArsR As(III) binds to Cys95, Cys96 and Cys102 from the same monomer, while, in CgArsR, to Cys15, Cys16 from one monomer and Cys55 from the other monomer. The dimer interfaces of these structures showed distinct differences from other members of the ArsR/SmtB family of proteins, which potentially renders multiple options for evolving metal(loid) binding sites in this family of proteins. Also, CgArsR presents a new alpha2-N binding site, not the previously predicted alpha3-N site. Despite differences in the location of the binding cysteines in the primary sequences of these proteins, the two metal binding sites are almost congruent on their structures, an example of convergent evolution. Analyses of the electrostatic surface of the proteins at the DNA binding domain indicate that there two different modes of derepression in the ArsR/SmtB family of metalloregulatory proteins. Structures of two ArsR As(III)-responsive transcriptional repressors: Implications for the mechanism of derepression.,Prabaharan C, Kandavelu P, Packianathan C, Rosen BP, Thiyagarajan S J Struct Biol. 2019 May 25. pii: S1047-8477(19)30113-3. doi:, 10.1016/j.jsb.2019.05.009. PMID:31136796 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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