TY - JOUR
T1 - A Symmetrical Tetramer for S. aureus Pyruvate Carboxylase in Complex with Coenzyme A
AU - Yu, Linda P.C.
AU - Xiang, Song
AU - Lasso, Gorka
AU - Gil, David
AU - Valle, Mikel
AU - Tong, Liang
N1 - Funding Information:
We thank Randy Abramowitz and John Schwanof for setting up the X4A and X4C beamlines at the NSLS, Melisa Lázaro for assistance during cryo-EM image processing, C. Huang for careful reading of the manuscript, and W. W. Cleland for helpful discussions. This research is supported in part by a grant from the National Institutes of Health (DK067238, to L.T.), the Etortek Research Programmes 2007/2009 (Department of Industry, Tourism and Trade of the Government of the Autonomous Community of the Basque Country), and by the Innovation Technology Department of the Bizkaia County (to M.V.).
PY - 2009/6/10
Y1 - 2009/6/10
N2 - Pyruvate carboxylase (PC) is a conserved metabolic enzyme with important cellular functions. We report crystallographic and cryo-electron microscopy (EM) studies of Staphylococcus aureus PC (SaPC) in complex with acetyl-CoA, an allosteric activator, and mutagenesis, biochemical, and structural studies of the biotin binding site of its carboxyltransferase (CT) domain. The disease-causing A610T mutation abolishes catalytic activity by blocking biotin binding to the CT active site, and Thr908 might play a catalytic role in the CT reaction. The crystal structure of SaPC in complex with CoA reveals a symmetrical tetramer, with one CoA molecule bound to each monomer, and cryo-EM studies confirm the symmetrical nature of the tetramer. These observations are in sharp contrast to the highly asymmetrical tetramer of Rhizobium etli PC in complex with ethyl-CoA. Our structural information suggests that acetyl-CoA promotes a conformation for the dimer of the biotin carboxylase domain of PC that might be catalytically more competent.
AB - Pyruvate carboxylase (PC) is a conserved metabolic enzyme with important cellular functions. We report crystallographic and cryo-electron microscopy (EM) studies of Staphylococcus aureus PC (SaPC) in complex with acetyl-CoA, an allosteric activator, and mutagenesis, biochemical, and structural studies of the biotin binding site of its carboxyltransferase (CT) domain. The disease-causing A610T mutation abolishes catalytic activity by blocking biotin binding to the CT active site, and Thr908 might play a catalytic role in the CT reaction. The crystal structure of SaPC in complex with CoA reveals a symmetrical tetramer, with one CoA molecule bound to each monomer, and cryo-EM studies confirm the symmetrical nature of the tetramer. These observations are in sharp contrast to the highly asymmetrical tetramer of Rhizobium etli PC in complex with ethyl-CoA. Our structural information suggests that acetyl-CoA promotes a conformation for the dimer of the biotin carboxylase domain of PC that might be catalytically more competent.
KW - PROTEINS
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U2 - 10.1016/j.str.2009.04.008
DO - 10.1016/j.str.2009.04.008
M3 - Article
C2 - 19523900
AN - SCOPUS:66349116676
SN - 0969-2126
VL - 17
SP - 823
EP - 832
JO - Structure
JF - Structure
IS - 6
ER -