TY - JOUR
T1 - Multiple protein domains contribute to the action of the copper chaperone for superoxide dismutase
AU - Schmidt, Paul J.
AU - Rae, Tracey D.
AU - Pufahl, Robert A.
AU - Hamma, Tomoko
AU - Strain, Jeff
AU - O'Halloran, Thomas V.
AU - Culotta, Valeria C.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1999/8/20
Y1 - 1999/8/20
N2 - The copper chaperone for superoxide dismutase (SOD1) inserts the catalytic metal cofactor into SOD1 by an unknown mechanism. We demonstrate here that this process involves the cooperation of three distinct regions of the copper chaperone for SOD1 (CCS): an amino-terminal Domain I homologous to the Atx1p metallochaperone, a central portion (Domain II) homologous to SOD1, and a short carboxyl-terminal peptide unique to CCS molecules (Domain III). These regions fold into distinct polypeptide domains as revealed through proteolysis protection studies. The biological roles of the yeast CCS domains were examined in yeast cells. Surprisingly, Domain I was found to be necessary only under conditions of strict copper limitation. Domain I and Atx1p were not interchangeable in vivo, underscoring the specificity of the corresponding metallochaperones. A putative copper site in Domain II was found to be irrelevant to yeast CCS activity, but SOD1 activation invariably required a CXC in Domain III that binds copper. Copper binding to purified yeast CCS induced allosteric conformational changes in Domain III and also enhanced homodimer formation of the polypeptide. Our results are consistent with a model whereby Domain I recruits cellular copper, Domain II facilitates target recognition, and Domain III, perhaps in concert with Domain I, mediates copper insertion into apo-SOD1.
AB - The copper chaperone for superoxide dismutase (SOD1) inserts the catalytic metal cofactor into SOD1 by an unknown mechanism. We demonstrate here that this process involves the cooperation of three distinct regions of the copper chaperone for SOD1 (CCS): an amino-terminal Domain I homologous to the Atx1p metallochaperone, a central portion (Domain II) homologous to SOD1, and a short carboxyl-terminal peptide unique to CCS molecules (Domain III). These regions fold into distinct polypeptide domains as revealed through proteolysis protection studies. The biological roles of the yeast CCS domains were examined in yeast cells. Surprisingly, Domain I was found to be necessary only under conditions of strict copper limitation. Domain I and Atx1p were not interchangeable in vivo, underscoring the specificity of the corresponding metallochaperones. A putative copper site in Domain II was found to be irrelevant to yeast CCS activity, but SOD1 activation invariably required a CXC in Domain III that binds copper. Copper binding to purified yeast CCS induced allosteric conformational changes in Domain III and also enhanced homodimer formation of the polypeptide. Our results are consistent with a model whereby Domain I recruits cellular copper, Domain II facilitates target recognition, and Domain III, perhaps in concert with Domain I, mediates copper insertion into apo-SOD1.
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U2 - 10.1074/jbc.274.34.23719
DO - 10.1074/jbc.274.34.23719
M3 - Article
C2 - 10446130
AN - SCOPUS:0033588249
SN - 0021-9258
VL - 274
SP - 23719
EP - 23725
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 34
ER -