Identification of the axial heme ligands of cytochrome b 556 in succinate: Ubiquinone oxidoreductase from Escherichia coli

FEBS Letters

Peterson, Jim²  Gennis, Robert B.¹  Vibat, Cecile¹ 

[1] School of Chemical Sciences, University of Illinois, 505 South Mathews Street, Urbana, IL 61801, USA;Department of Chemistry, The University of Alabama, Box 870336, Tuscaloosa, AL 35487, USA

关键词: Heme protein;    Axial ligand;    EPR;    MCD;    Succinate dehydrogenase;    EDTA;    ethylenediaminetetracetic acid;    EPR;    electron paramagnetic resonance;    HEPES;    N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid);    MCD;    magnetic circular dichroism;   

DOI  :  10.1016/0014-5793(94)01189-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown