Porto, Tatiana V and Hough, Michael A and Worrall, Jonathan AR (2015) Structural insights into conformational switching in the copper metalloregulator CsoR from<i>Streptomyces lividans</i>. Acta Crystallographica Section D Biological Crystallography, 71 (9). pp. 1872-1878. DOI https://doi.org/10.1107/s1399004715013012
Porto, Tatiana V and Hough, Michael A and Worrall, Jonathan AR (2015) Structural insights into conformational switching in the copper metalloregulator CsoR from<i>Streptomyces lividans</i>. Acta Crystallographica Section D Biological Crystallography, 71 (9). pp. 1872-1878. DOI https://doi.org/10.1107/s1399004715013012
Porto, Tatiana V and Hough, Michael A and Worrall, Jonathan AR (2015) Structural insights into conformational switching in the copper metalloregulator CsoR from<i>Streptomyces lividans</i>. Acta Crystallographica Section D Biological Crystallography, 71 (9). pp. 1872-1878. DOI https://doi.org/10.1107/s1399004715013012
Abstract
<jats:p>Copper-sensitive operon repressors (CsoRs) act to sense cuprous ions and bind them with a high affinity under copper stress in many bacteria. The binding of copper(I) leads to a conformational change in their homotetramer structure, causing disassembly of the operator DNA–CsoR complex and evoking a transcriptional response. Atomic-level structural insight into the conformational switching mechanism between the apo and metal-bound states is lacking. Here, a new X-ray crystal structure of the CsoR from<jats:italic>Streptomyces lividans</jats:italic>is reported and compared with a previously reported<jats:italic>S. lividans</jats:italic>CsoR X-ray structure crystallized under different conditions. Based on evidence from this new X-ray structure, it is revealed that the conformational switching between states centres on a concertina effect at the C-terminal end of each α2 helix in the homotetramer. This drives the Cys104 side chain, a copper(I)-ligating residue, into a position enabling copper(I) coordination and as a result disrupts the α2-helix geometry, leading to a compacting and twisting of the homotetramer structure. Strikingly, the conformational switching induces a redistribution of electrostatic surface potential on the tetrameric DNA-binding face, which in the copper(I)-bound state would no longer favour interaction with the mode of operator DNA binding.</jats:p>
Item Type: | Article |
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Uncontrolled Keywords: | CsoR; allostery; copper; metalloregulator |
Subjects: | Q Science > QH Natural history > QH301 Biology |
Divisions: | Faculty of Science and Health Faculty of Science and Health > Life Sciences, School of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 04 Sep 2015 10:56 |
Last Modified: | 07 Aug 2024 19:47 |
URI: | http://repository.essex.ac.uk/id/eprint/14771 |