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Identification of the axial heme ligands of cytochrome b 556 in succinate: Ubiquinone oxidoreductase from Escherichia coli
Author(s) -
Peterson Jim,
Vibat Cecile,
Gennis Robert B.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)01189-3
Subject(s) - escherichia coli , oxidoreductase , heme , cytochrome , cytochrome b , biochemistry , chemistry , identification (biology) , microbiology and biotechnology , biology , stereochemistry , enzyme , gene , botany , mitochondrial dna
Electron paramagnetic resonance (EPR) and near‐infrared magnetic circular dichroism (MCD) have been used to identify the ligands to the cytochrome b 556 component of succinate: ubiquinone oxidoreductase (succinate dehydrogenase) from Escherichia coli . The ‘highly axial low spin’ (HALS) EPR spectrum suggests bis(histidine) ligation of the heme with the histidines in a staggered configuration. The near‐infrared MCD spectrum exhibits a low energy maximum at 1600 nm which is also clearly indicative of bis(histidine) ligation of the heme iron. The data unambiguously demonstrate that the heme b 556 is ligated to E. coli succinate dehydrogenase via two histidines.