4BPY

Crystal structure of the C90A mutant of the Sco copper chaperone protein from Streptomyces lividans

4BPY の概要

• エントリーDOI: 10.2210/pdb4bpy/pdb
• 分子名称: SCO PROTEIN (2 entities in total)
• 機能のキーワード: copper homeostasis, chaperone, homeostasis
• 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: 19059.48

構造登録者

Blundell, K.L.I.M.,Hough, M.A.,Worrall, J.A.R. (登録日: 2013-05-29, 公開日: 2014-03-05, 最終更新日: 2024-11-13)

主引用文献

Blundell, K.L.I.M.,Hough, M.A.,Vijgenboom, E.,Worrall, J.A.R.
Structural and Mechanistic Insights Into an Extracytoplasmic Copper Trafficking Pathway in Streptomyces Lividans.
Biochem.J., 459:525-, 2014

PubMed Abstract: In Streptomyces lividans an extracytoplasmic copper-binding Sco protein plays a role in two unlinked processes: (i) initiating a morphological development switch and (ii) facilitating the co-factoring of the CuA domain of CcO (cytochrome c oxidase). How Sco obtains copper once secreted to the extracytoplasmic environment is unknown. In the present paper we report on a protein possessing an HX₆MX₂₁HXM motif that binds a single cuprous ion with subfemtomolar affinity. High-resolution X-ray structures of this extracytoplasmic copper chaperone-like protein (ECuC) in the apo- and Cu(I)-bound states reveal that the latter possesses a surface-accessible cuprous-ion-binding site located in a dish-shaped region of β-sheet structure. A cuprous ion is transferred under a favourable thermodynamic gradient from ECuC to Sco with no back transfer occurring. The ionization properties of the cysteine residues in the Cys⁸⁶xxxCys⁹⁰ copper-binding motif of Sco, together with their positional locations identified from an X-ray structure of Sco, suggests a role for Cys⁸⁶ in initiating an inter-complex ligand-exchange reaction with Cu(I)-ECuC. Generation of the genetic knockouts, Δsco, Δecuc and Δsco/ecuc, and subsequent in vivo assays lend support to the existence of a branched extracytoplasmic copper-trafficking pathway in S. lividans. One branch requires both Sco and to a certain extent ECuC to cofactor the CuA domain, whereas the other uses only Sco to deliver copper to a cuproenzyme to initiate morphological development.

PubMed: 24548299
DOI: 10.1042/BJ20140017

実験手法

X-RAY DIFFRACTION (1.4 Å)