Tuna ferrocytochrome c and ferricytochrome c have been refined independently at high resolution (1.5 A and 1.8 A) to crystallographic residual errors of 17.3% and 20.8%, respectively. Small but significant conformational differences are seen surrounding a buried water molecule that is hydrogen bonded to Asn-52, Tyr-67, and Thr-78 ...
Tuna ferrocytochrome c and ferricytochrome c have been refined independently at high resolution (1.5 A and 1.8 A) to crystallographic residual errors of 17.3% and 20.8%, respectively. Small but significant conformational differences are seen surrounding a buried water molecule that is hydrogen bonded to Asn-52, Tyr-67, and Thr-78. In the oxidized state, this water molecule is 1.0 A closer to the heme and the heme has moved 0.15 A out of its heme crevice; both changes lead to a more polar microenvironment for the heme. Chemical modification studies, patterns of evolutionary conservatism, structural differences in bacterial cytochromes, and x-ray studies all agree that the "active site" for cytochrome c is bounded by lysines 8, 13,27, 72, 79, 86, and 87 (thus containing the evolutionary conservative 72-87 loop) and has the buried water molecule just below its surface and the opening of the heme crevice slightly to one side.
Related Citations:
Conformation Change of Cytochrome C. I. Ferrocytochrome C Structure Refined at 1.5 Angstroms Resolution Takano, T., Dickerson, R.E. (1981) J Mol Biol 153: 79
Conformation Change of Cytochrome C. II. Ferricytochrome C Refinement at 1.8 Angstroms and Comparison with the Ferrocytochrome Structure Takano, T., Dickerson, R.E. (1981) J Mol Biol 153: 95
Cytochrome C and the Evolution of Energy Metabolism Dickerson, R.E. (1980) Sci Am 242: 136
Internal Mobility of Ferrocytochrome C Northrup, S.H., Pear, M.R., Mccammon, J.A., Karplus, M., Takano, T. (1980) Nature 287: 659
Tuna Cytochrome C at 2.0 Angstroms Resolution. II. Ferrocytochrome Structure Analysis Takano, T., Trus, B.L., Mandel, N., Mandel, G., Kallai, O.B., Swanson, R., Dickerson, R.E. (1977) J Biol Chem 252: 776
Tuna Cytochrome C at 2.0 Angstroms Resolution. I. Ferricytochrome Structure Analysis Swanson, R., Trus, B.L., Mandel, N., Mandel, G., Kallai, O.B., Dickerson, R.E. (1977) J Biol Chem 252: 759
The Structure of Ferrocytochrome C at 2.45 Angstroms Resolution Takano, T., Kallai, O.B., Swanson, R., Dickerson, R.E. (1973) J Biol Chem 248: 5234
The Structure and History of an Ancient Protein Dickerson, R.E. (1972) Sci Am 226: 58
Organizational Affiliation:
the Department of Molecular and Cellular Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, and.
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