4UIG
Structure of the copper sensitive operon repressor from Streptomyces lividans at pH6
Summary for 4UIG
| Entry DOI | 10.2210/pdb4uig/pdb |
| Descriptor | COPPER SENSITIVE OPERON REPRESSOR, SULFATE ION (3 entities in total) |
| Functional Keywords | transcription, bacterial proteins, regulon, repressor proteins, stress, allostery |
| Biological source | STREPTOMYCES LIVIDANS |
| Total number of polymer chains | 1 |
| Total formula weight | 14954.69 |
| Authors | Porto, T.,Hough, M.A.,Worrall, J.A.R. (deposition date: 2015-03-30, release date: 2015-09-09, Last modification date: 2024-01-10) |
| Primary citation | Porto, T.V.,Hough, M.A.,Worrall, J.A.R. Structural Insights Into Conformational Switching in the Copper Metalloregulator Csor from Streptomyces Lividans Acta Crystallogr.,Sect.D, 71:1872-, 2015 Cited by PubMed Abstract: 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 Streptomyces lividans is reported and compared with a previously reported S. lividans 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. PubMed: 26327377DOI: 10.1107/S1399004715013012 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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