3ZK0

The crystal structure of a Cu(I) metallochaperone from Streptomyces lividans in its apo form

Summary for 3ZK0

• Entry DOI: 10.2210/pdb3zk0/pdb
• Related: 3ZJA
• Descriptor: SCO3965 (2 entities in total)
• Functional Keywords: chaperone, metallochaperone
• Biological source: STREPTOMYCES LIVIDANS
• Total number of polymer chains: 1
• Total formula weight: 14667.10

Authors

Blundell, K.L.I.M.,Hough, M.,Worrall, J.A.R. (deposition date: 2013-01-21, release date: 2014-01-29, Last modification date: 2023-12-20)

Primary citation

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

Experimental method

X-RAY DIFFRACTION (1.7 Å)