Journal article

CopC protein from Pseudomonas syringae: Intermolecular transfer of copper from both the copper(I) and copper(II) sites

M Koay, LY Zhang, BS Yang, MJ Maher, ZG Xiao, AG Wedd

INORGANIC CHEMISTRY | AMER CHEMICAL SOC | Published : 2005

Abstract

The CopC protein from Pseudomonas syringae pathovar tomato is expressed as one of four proteins encoded by the operon CopABCD that is responsible for copper resistance. It is a small soluble molecule (10.5 kDa) with a beta-barrel structure and features two distinct copper binding sites, which are highly specific for Cu(I) (K(D) > or = 10(-)(13)) and Cu(II) (K(D) approximately 10(-)(15)). These dissociation constants were estimated via ligand competition experiments monitored by electronic spectral and fluorescence probes. The chemistries of the two copper sites are interdependent. When the Cu(II) site is empty, the Cu(I) ion is oxidized by air, but when both sites are occupied, the molecule ..

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