4UIG

Structure of the copper sensitive operon repressor from Streptomyces lividans at pH6

4UIG の概要

• エントリーDOI: 10.2210/pdb4uig/pdb
• 分子名称: COPPER SENSITIVE OPERON REPRESSOR, SULFATE ION (3 entities in total)
• 機能のキーワード: transcription, bacterial proteins, regulon, repressor proteins, stress, allostery
• 由来する生物種: STREPTOMYCES LIVIDANS
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 14954.69

構造登録者

Porto, T.,Hough, M.A.,Worrall, J.A.R. (登録日: 2015-03-30, 公開日: 2015-09-09, 最終更新日: 2024-01-10)

主引用文献

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

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: 26327377
DOI: 10.1107/S1399004715013012

実験手法

X-RAY DIFFRACTION (2 Å)