1I55

CYTOCHROME C (TUNA) WITH 2ZN:1FE MIXED-METAL PORPHYRINS

1I55 の概要

• エントリーDOI: 10.2210/pdb1i55/pdb
• 関連するPDBエントリー: 3CYT
• 分子名称: CYTOCHROME C, HEME C, PROTOPORPHYRIN IX CONTAINING ZN, ... (4 entities in total)
• 機能のキーワード: cytochrome c, electron transfer, zinc-porphyrin, electron transport
• 由来する生物種: Thunnus thynnus (bluefin tuna)
• 細胞内の位置: Mitochondrion matrix: P81459
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 25269.26

構造登録者

Crane, B.R.,Tezcan, F.A.,Winkler, J.R.,Gray, H.B. (登録日: 2001-02-24, 公開日: 2001-05-09, 最終更新日: 2024-11-13)

主引用文献

Tezcan, F.A.,Crane, B.R.,Winkler, J.R.,Gray, H.B.
Electron tunneling in protein crystals.
Proc.Natl.Acad.Sci.USA, 98:5002-5006, 2001

PubMed Abstract: The current understanding of electron tunneling through proteins has come from work on systems where donors and acceptors are held at fixed distances and orientations. The factors that control electron flow between proteins are less well understood, owing to uncertainties in the relative orientations and structures of the reactants during the very short time that tunneling occurs. As we report here, the way around such structural ambiguity is to examine oxidation-reduction reactions in protein crystals. Accordingly, we have measured and analyzed the kinetics of electron transfer between native and Zn-substituted tuna cytochrome c (cyt c) molecules in crystals of known structure. Electron transfer rates [(320 s(-1) for *Zn-cyt c --> Fe(III)-cyt c; 2000 s(-1) for Fe(II)-cyt c --> Zn-cyt c(+))] over a Zn-Fe distance of 24.1 A closely match those for intraprotein electron tunneling over similar donor-acceptor separations. Our results indicate that van der Waals interactions and water-mediated hydrogen bonds are effective coupling elements for tunneling across a protein-protein interface.

PubMed: 11296248
DOI: 10.1073/pnas.081072898

実験手法

X-RAY DIFFRACTION (2 Å)