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Structural models for the alkaline conformers of yeast iso ‐1‐ferricytochrome c
Author(s) -
Ness Steven R.,
Lo Terence P.,
Mauk A. Grant
Publication year - 2000
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1560/pk7u-lepj-etb5-997x
Subject(s) - chemistry , conformational isomerism , cytochrome c , heme , protein structure , crystallography , protein tertiary structure , yeast , ligand (biochemistry) , conformational change , hemeprotein , molecular dynamics , stereochemistry , biophysics , biochemistry , computational chemistry , molecule , enzyme , receptor , organic chemistry , mitochondrion , biology
Abstract Structural models for three alkaline conformers of yeast iso ‐1‐ferricytochrome c have been calculated from the atomic coordinates of the native protein through the use of molecular dynamics simulation. In the three models produced by this work, the Met80 axial ligand to the heme iron has been replaced by either Lys72, Lys73, or Lys79, and the related changes in structure of the cyto‐chrome are described. The principal changes in cytochrome structure predicted to result from this pH‐linked change in axial ligation involve location of residues 70–80, a region of the protein sequence that is phylogenetically conserved. The remainder of the protein fold in each model is essentially unchanged from the structure of the native protein, which is consistent with available spectroscopic information. The observation that this highly conserved region is apparently integrally involved in this conformational change may be interpreted as indicating a possible physiological role for the pH‐linkage of ferricytochrome c structure.