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

ABSTRACT: 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 1.86 Å. CgArsR crystallized in P2₁2₁2₁ and diffracted up to 1.6 Å. 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 Cy

SUBMITTER: Prabaharan C 

PROVIDER: S-EPMC6689322 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature