A directional electron transfer regulator based on heme‐chain architecture in the small tetraheme cytochrome c from Shewanella oneidensis

FEBS Letters

Akutsu, Hideo²  Harada, Erisa²  Imabayashi, Shinichiro¹  Ozawa, Kiyoshi¹  Cusanovich, Michael A³  Kumagai, Jiro¹  Tsapin, Alexandre S⁴  Meyer, Terrance E³  Nealson, Kenneth H⁴ 

[1] Faculty of Engineering, Yokohama National University, Hodogaya-ku, Yokohama 240-8501, Japan;Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan;Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, AZ 85721, USA;Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA

关键词: Redox potential;    Tetraheme cytochrome;    Heme architecture;    Cooperativity;    NMR;    Polarography;    STC;    small tetraheme cytochrome c;    SFR;    soluble fumarate reductase;    So;    Shewanella oneidensis;    Sf;    Shewanella frigidimarina;    Si;    i-electron reduced state;    FAD;    flavin adenine dinucleotide;   

DOI  :  10.1016/S0014-5793(02)03696-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The macroscopic and microscopic redox potentials of the four hemes of the small tetraheme cytochrome c from Shewanella oneidensis were determined. The microscopic redox potentials show that the order of reduction is from hemes in the C-terminal domain (hemes 3 and 4) to the N-terminal domain (heme 1), demonstrating the polarization of the tetraheme chain during reduction. This makes heme 4 the most efficient electron delivery site. Furthermore, multi-step reduction of other redox centers through either heme 4 or heme 3 is shown to be possible. This has provided new insights into the two-electron reduction of the flavin in the homologous flavocytochrome c–fumarate reductase.

【 授权许可】

Unknown