Cytochrome c554 from the denitrifying bacterium Achromobacter cycloclastes is a monoheme class II c-type cytochrome with a His-Met axial coordination at neutral pH. The amino acid composition and the N-terminal sequence of the cytochrome have been determined. Subsequent determination of the pH-dependence of the redox potential and examination of the EPR and MCD spectra of ferricytochrome c554 revealed a new form at high pH values made apparent with both spectroscopies. These observations are consistent with the presence of lysine as the axial ligand for which methionine substitutes at high pH values.
|Number of pages||9|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 1 Jan 1994|