6EK9

Cytosolic copper storage protein Csp from Streptomyces lividans: Cu loaded form

Summary for 6EK9

• Entry DOI: 10.2210/pdb6ek9/pdb
• Related: 6EI0
• Descriptor: Cytosolic copper storage protein, COPPER (I) ION (3 entities in total)
• Functional Keywords: copper storage, cytocolic, metal binding protein
• Biological source: Streptomyces lividans
• Total number of polymer chains: 1
• Total formula weight: 13889.39

Authors

Straw, M.L.,Chaplin, A.K.,Hough, M.A.,Worrall, J.A.R. (deposition date: 2017-09-25, release date: 2018-08-08, Last modification date: 2024-01-17)

Primary citation

Straw, M.L.,Chaplin, A.K.,Hough, M.A.,Paps, J.,Bavro, V.N.,Wilson, M.T.,Vijgenboom, E.,Worrall, J.A.R.
A cytosolic copper storage protein provides a second level of copper tolerance in Streptomyces lividans.
Metallomics, 10:180-193, 2018

PubMed Abstract: Streptomyces lividans has a distinct dependence on the bioavailability of copper for its morphological development. A cytosolic copper resistance system is operative in S. lividans that serves to preclude deleterious copper levels. This system comprises of several CopZ-like copper chaperones and P-type ATPases, predominantly under the transcriptional control of a metalloregulator from the copper sensitive operon repressor (CsoR) family. In the present study, we discover a new layer of cytosolic copper resistance in S. lividans that involves a protein belonging to the newly discovered family of copper storage proteins, which we have named Ccsp (cytosolic copper storage protein). From an evolutionary perspective, we find Ccsp homologues to be widespread in Bacteria and extend through into Archaea and Eukaryota. Under copper stress Ccsp is upregulated and consists of a homotetramer assembly capable of binding up to 80 cuprous ions (20 per protomer). X-ray crystallography reveals 18 cysteines, 3 histidines and 1 aspartate are involved in cuprous ion coordination. Loading of cuprous ions to Ccsp is a cooperative process with a Hill coefficient of 1.9 and a CopZ-like copper chaperone can transfer copper to Ccsp. A Δccsp mutant strain indicates that Ccsp is not required under initial copper stress in S. lividans, but as the CsoR/CopZ/ATPase efflux system becomes saturated, Ccsp facilitates a second level of copper tolerance.

PubMed: 29292456
DOI: 10.1039/c7mt00299h

Experimental method

X-RAY DIFFRACTION (1.5 Å)