Evidence for N coordination to Fe in the [2Fe‐2S] center in yeast mitochondrial complex III Comparison with similar findings for analogous bacterial [2Fe‐2S] proteins

FEBS Letters

Palmer, Graham¹  Telser, Joshua³  Hoffman, Brian M.³  LoBrutto, Russell²  Tsai, Ah-Lim¹  Ohnishi, Tomoko²  Simpkin, David¹ 

[1] Department of Biochemistry, Rice University, Houston, TX 77251, USA;Department of Biochemistry & Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA;Department of Chemistry, Northwestern University, Evanston, IL 60201, USA

关键词: Mitochondria;    Complex III;    Iron-sulfur cluster;    ENDOR;    ESEEM;   

DOI  :  10.1016/0014-5793(87)80024-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Yeast mitochondrial complex III contains a subunit with a [2Fe-2S] cluster (the Rieske center) that has unusual physical and chemical properties. For apparently similar centers isolated from bacteria, it has been shown by electron nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM) measurements that these [2Fe-2S] centers are coordinated by at least one and probably two nitrogen ligands. This work describes similar ENDOR and ESEEM studies on the intact mitochondrial complex. We find that this [2Fe-2S] cluster exhibits ESEEM and ENDOR properties that appear to be indistinguishable from those observed with the isolated bacterial systems. Furthermore, changes in EPR lineshape that occur as complex III is progressively reduced are not accompanied by any changes in the nitrogen coupling parameters. This spectroscopic evidence for nitrogen coordination is supported by published sequence data on four Rieske iron-sulfur subunits. It seems likely that this is a general characteristic of such [2Fe-2S] redox active centers.

【 授权许可】

Unknown