Solution structure of the yeast copper transporter domain Ccc2a in the apo and Cu(I)-loaded states.Banci, L., Bertini, I., Ciofi-Baffoni, S., Huffman, D.L., O'Halloran, T.V.
(2001) J Biol Chem 276: 8415-8426
- PubMed: 11083871
- DOI: https://doi.org/10.1074/jbc.M008389200
- Primary Citation of Related Structures:
- PubMed Abstract:
Ccc2 is an intracellular copper transporter in Saccharomyces cerevisiae and is a physiological target of the copper chaperone Atx1. Here we describe the solution structure of the first N-terminal MTCXXC metal-binding domain, Ccc2a, both in the presence and absence of Cu(I). For Cu(I)-Ccc2a, 1944 meaningful nuclear Overhauser effects were used to obtain a family of 35 structures with root mean square deviation to the average structure of 0.36 +/- 0.06 A for the backbone and 0.79 +/- 0.05 A for the heavy atoms. For apo-Ccc2a, 1970 meaningful nuclear Overhauser effects have been used with 35 (3)J(HNHalpha) to obtain a family of 35 structures with root mean square deviation to the average structure of 0.38 +/- 0.06 A for the backbone and 0.82 +/- 0.07 A for the heavy atoms. The protein exhibits a betaalphabetabetaalphabeta, ferrodoxin-like fold similar to that of its target Atx1 and that of a human counterpart, the fourth metal-binding domain of the Menkes protein. The overall fold remains unchanged upon copper loading, but the copper-binding site itself becomes less disordered. The helical context of the copper-binding site, and the copper-induced conformational changes in Ccc2a differ from those in Atx1. Ccc2a presents a conserved acidic surface which complements the basic surface of Atx1 and a hydrophobic surface. These results open new mechanistic aspects of copper transporter domains with physiological copper donor and acceptor proteins.
Magnetic Resonance Center and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, Sesto Fiorentino, Florence, 50019, Italy.