5FIG: APO-CSP3 (COPPER STORAGE PROTEIN 3) FROM BACILLUS SUBTILIS

Citation:
Abstract
Bacteria are thought to avoid using the essential metal ion copper in their cytosol due to its toxicity. Herein we characterize Csp3, the cytosolic member of a new family of bacterial copper storage proteins from Methylosinus trichosporium OB3b and Bacillus subtilis. These tetrameric proteins possess a large number of Cys residues that point into the cores of their four-helix bundle monomers. The Csp3 tetramers can bind a maximum of approximately 80 Cu(I) ions, mainly via thiolate groups, with average affinities in the (1-2) x 10(17) M(-1) range. Cu(I) removal from these Csp3s by higher affinity potential physiological partners and small-molecule ligands is very slow, which is unexpected for a metal-storage protein. In vivo data demonstrate that Csp3s prevent toxicity caused by the presence of excess copper. Furthermore, bacteria expressing Csp3 accumulate copper and are able to safely maintain large quantities of this metal ion in their cytosol. This suggests a requirement for storing copper in this compartment of Csp3-producing bacteria.
PDB ID: 5FIGDownload
MMDB ID: 143930
PDB Deposition Date: 2015/9/25
Updated in MMDB: 2016/10
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 5FIG: tetrameric; determined by author and by software (PISA)
Molecular Components in 5FIG
Label Count Molecule
Proteins (4 molecules)
4
Csp3
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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