2VHD

Crystal Structure Of The Di-Haem Cytochrome C Peroxidase From Pseudomonas aeruginosa - Mixed Valence Form

2VHD の概要

• エントリーDOI: 10.2210/pdb2vhd/pdb
• 関連するPDBエントリー: 1EB7
• 分子名称: CYTOCHROME C551 PEROXIDASE, HEME C, CALCIUM ION, ... (4 entities in total)
• 機能のキーワード: iron, heme, transport, peroxidase, metal-binding, oxidoreductase, electron transport
• 由来する生物種: PSEUDOMONAS AERUGINOSA
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 72705.04

構造登録者

Echalier, A.,Brittain, T.,Wright, J.,Boycheva, S.,Mortuza, G.B.,Fulop, V.,Watmough, N.J. (登録日: 2007-11-20, 公開日: 2008-02-12, 最終更新日: 2024-11-13)

主引用文献

Echalier, A.,Brittain, T.,Wright, J.,Boycheva, S.,Mortuza, G.B.,Fulop, V.,Watmough, N.J.
Redox-Linked Structural Changes Associated with the Formation of a Catalytically Competent Form of the Diheme Cytochrome C Peroxidase from Pseudomonas Aeruginosa
Biochemistry, 47:1947-, 2008

PubMed Abstract: A recombinant form of the prototypic diheme bacterial cytochrome c peroxidase (BCCP) from Pseudomonas aeruginosa (PsaCCP) has been expressed in Escherichia coli and purified to homogeneity. This material was used to carry out the first integrated biochemical, spectroscopic and structural investigation of the factors leading to reductive activation of this class of enzymes. A single, tightly bound, Ca2+ ion (K = 3 x 10(10) M-1) found at the domain interface of both the fully oxidized and mixed-valence forms of the enzyme is absolutely required for catalytic activity. Reduction of the electron-transferring (high-potential) heme in the presence of Ca2+ ions triggers substantial structural rearrangements around the active-site (low-potential) heme to allow substrate binding and catalysis. The enzyme also forms a mixed-valence state in the absence of Ca2+ ions, but a combination of electronic absorption, and EPR spectroscopies suggests that under these circumstances the low potential heme remains six-coordinate, unable to bind substrate and therefore catalytically inactive. Our observations strongly suggest that the two mixed-valence forms of native PsaCCP reported previously by Foote and colleagues (Foote, N., Peterson, J., Gadsby, P., Greenwood, C., and Thomson, A. (1985) Biochem. J. 230, 227-237) correspond to the Ca2+-loaded and -depleted forms of the enzyme.

PubMed: 18217775
DOI: 10.1021/BI702064F

実験手法

X-RAY DIFFRACTION (2.3 Å)