Crystal structure of the copper chaperone for superoxide dismutase

Cellular systems for handling transition metal ions hare been identified, b ut little is known about the structure and function of the specific traffic king proteins. The 1.8 Angstrom resolution structure of the past copper cha perone for superoxide dismutase (yCCS) reveals a protein composed of two do mains. The N-terminal domain is very similar to the metallochaperone protei n Atx1 and is likely to play a role in copper delivery and/or uptake. The s econd domain resembles the physiological target of yCCS, superoxide dismuta se I (SOD1), in overall fold, but lacks all of the structural elements invo lved in catalysis. In the crystal, two SOD1-like domains interact to form a dimer. The subunit interface is remarkably similar to that in SOD1, sugges ting a structural basis for target recognition by this metallochaperone.