6Q58

Copper loading to a cytosolic copper storage protein from Streptomyces lividans (five coppers)

6Q58 の概要

• エントリーDOI: 10.2210/pdb6q58/pdb
• 分子名称: Cytosolic copper storage protein, COPPER (I) ION (3 entities in total)
• 機能のキーワード: copper, cytosolic, storage protein, streptomyces livdians, metal binding protein
• 由来する生物種: Streptomyces coelicolor 1326
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 51094.55

構造登録者

Straw, M.L.,Hough, M.A.,Worrall, J.A.R. (登録日: 2018-12-07, 公開日: 2019-07-10, 最終更新日: 2024-01-24)

主引用文献

Straw, M.L.,Hough, M.A.,Wilson, M.T.,Worrall, J.A.R.
A Histidine Residue and a Tetranuclear Cuprous-thiolate Cluster Dominate the Copper Loading Landscape of a Copper Storage Protein from Streptomyces lividans.
Chemistry, 25:10678-10688, 2019

PubMed Abstract: The chemical basis for protecting organisms against the toxic effect imposed by excess cuprous ions is to constrain this through high-affinity binding sites that use cuprous-thiolate coordination chemistry. In bacteria, a family of cysteine rich four-helix bundle proteins utilise thiolate chemistry to bind up to 80 cuprous ions. These proteins have been termed copper storage proteins (Csp). The present study investigates cuprous ion loading to the Csp from Streptomyces lividans (SlCsp) using a combination of X-ray crystallography, site-directed mutagenesis and stopped-flow reaction kinetics with either aquatic cuprous ions or a chelating donor. We illustrate that at low cuprous ion concentrations, copper is loaded exclusively into an outer core region of SlCsp via one end of the four-helix bundle, facilitated by a set of three histidine residues. X-ray crystallography reveals the existence of polynuclear cuprous-thiolate clusters culminating in the assembly of a tetranuclear [Cu (μ -S-Cys) (Ν -His)] cluster in the outer core. As more cuprous ions are loaded, the cysteine lined inner core of SlCsp fills with cuprous ions but in a fluxional and dynamic manner with no evidence for the assembly of further intermediate polynuclear cuprous-thiolate clusters as observed in the outer core. Using site-directed mutagenesis a key role for His107 in the efficient loading of cuprous ions from a donor is established. A model of copper loading to SlCsp is proposed and discussed.

PubMed: 31111982
DOI: 10.1002/chem.201901411

実験手法

X-RAY DIFFRACTION (1.5 Å)