2LEL:
reference: Molecular basis of the cooperative binding of Cu(I) and Cu(II) to the CopK protein from Cupriavidus metallidurans CH34., Ash MR, Chong LX, Maher MJ, Hinds MG, Xiao Z, Wedd AG, Biochemistry. 2011 Nov 1;50(43):9237-47. Epub 2011 Oct 4. PMID: 21936507

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