Chaperone-mediated Cu+ delivery to Cu+ transport ATPases: requirement of nucleotide binding.

ABSTRACT: Cu(+)-ATPases drive the efflux of Cu(+) from the cell cytoplasm. During their catalytic/transport cycle, cytoplasmic Cu(+)-chaperones deliver the metal to the two transmembrane metal-binding sites (TM-MBSs) responsible for Cu(+) translocation. Here, using Archaeoglobus fulgidus Cu(+)-ATPase CopA and the C-terminal Cu(+)-chaperone domain of CopZ (Ct-CopZ), we describe the mechanism of Cu(+) transfer to both TM-MBSs. In absence of other ligands, Ct-CopZ transfers Cu(+) to wild-type CopA and to various CopA constructs lacking or having mutated cytoplasmic metal-binding domains, in a fashion consistent with occupancy of a single TM-MBS. Similar experiments performed in the presence of 2.5 mm ADP-Mg(2+), stabilizing an E1.ADP, lead to full occupancy of both TM-MBSs. In both cases, the transfer

SUBMITTER: Gonzalez-Guerrero M 

PROVIDER: S-EPMC2742845 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature