Functional and conformational properties of the exclusive C-domain from the Arabidopsis copper chaperone (CCH)

The Arabidopsis thaliana copper chaperone (CCH) is a small copper binding protein involved in copper trafficking. When compared to homologues from other eukaryotes, CCH has two different domains; the conserved N-domain and the plant-exclusive C-domain, a C-terminal extension with an unusual amino-acid composition. In order to characterize this extra C-domain, the CCH protein, the N-domain and the C-domain were all expressed separately in heterologous systems. While the N-domain retained the copper chaperone and antioxidant properties described for the yeast Atx1 and human HAH1 counterparts, the C-domain displayed particular structural properties that would be necessary to optimize copper ho…