7CPP

THE STRUCTURAL BASIS FOR SUBSTRATE-INDUCED CHANGES IN REDOX POTENTIAL AND SPIN EQUILIBRIUM IN CYTOCHROME P450(CAM)

7CPP の概要

• エントリーDOI: 10.2210/pdb7cpp/pdb
• 分子名称: CYTOCHROME P450-CAM, PROTOPORPHYRIN IX CONTAINING FE, NORCAMPHOR, ... (4 entities in total)
• 機能のキーワード: oxidoreductase(oxygenase)
• 由来する生物種: Pseudomonas putida
• 細胞内の位置: Cytoplasm : P00183
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 47315.52

構造登録者

Raag, R.,Poulos, T.L. (登録日: 1990-05-18, 公開日: 1991-07-15, 最終更新日: 2024-03-06)

主引用文献

Raag, R.,Poulos, T.L.
The structural basis for substrate-induced changes in redox potential and spin equilibrium in cytochrome P-450CAM.
Biochemistry, 28:917-922, 1989

PubMed Abstract: The crystal structures of cytochrome P-450CAM complexed with the alternative substrates norcamphor and adamantanone have been refined at 2.0-A resolution and compared with the native, camphor-bound form of the enzyme. Norcamphor lacks the 8-, 9-, and 10-methyl groups of camphor. Thus, specific interactions between these groups and phenylalanine 87 and valines 247 and 295 are missing in the norcamphor complex. As a result, norcamphor binds about 0.9 A further from the oxygen-binding site than does camphor, which allows sufficient room for a water molecule or hydroxide ion to remain coordinated with the heme iron atom. The larger adamantanone occupies a position closer to that of camphor and, as in the camphor-bound enzyme, the heme iron remains pentacoordinate with no solvent molecule coordinated as a sixth ligand. A comparison of crystallographic temperature factors indicates that norcamphor is more "loosely" bound than are either camphor or adamantanone, as might be expected from the relative sizes of the different substrates. The looser fit of norcamphor in the active-site pocket results in a less specific pattern of hydroxylation. The presence of an aqua ligand is the likely structural basis for the norcamphor-P-450CAM complex having both a lower redox potential and higher percentage of low-spin heme than do either the camphor-P-450CAM or adamantanone-P-450CAM complexes.

PubMed: 2713354
DOI: 10.1021/bi00428a077

実験手法

X-RAY DIFFRACTION (2 Å)