Molecular structure and metal-binding properties of the periplasmic CopK protein expressed in Cupriavidus metallidurans CH34 during copper challenge.

The copK gene is localized on the pMOL30 plasmid of Cupriavidus metallidurans CH34 within the complex cop cluster of genes, for which 21 genes have been identified. The expression of the corresponding periplasmic CopK protein is strongly upregulated in the presence of copper, leading to a high periplasmic accumulation. The structure and metal-binding properties of CopK were investigated by NMR and mass spectrometry.

Transcriptomic and proteomic analyses of the pMOL30-encoded copper resistance in Cupriavidus metallidurans strain CH34.

The four replicons of Cupriavidus metallidurans CH34 (the genome sequence was provided by the US Department of Energy-University of California Joint Genome Institute) contain two gene clusters putatively encoding periplasmic resistance to copper, with an arrangement of genes resembling that of the copSRABCD locus on the 2.1 Mb megaplasmid (MPL) of Ralstonia solanacearum, a closely related plant pathogen. One of the copSRABCD clusters was located on the 2.

Overexpression, purification, crystallization and crystallographic analysis of CopK of Cupriavidus metallidurans.

CopK of Cupriavidus metallidurans is a 93-amino-acid protein whose mature form (73 amino acids) has been purified and crystallized by the hanging-drop vapour-diffusion method in 100 mM citrate pH 3.5, 200 mM Li2SO4, 20%(w/v) glycerol, 13%(w/v) PEG 8000. Crystals display orthorhombic symmetry, with unit-cell parameters a = 57.