1JPZ

Crystal structure of a complex of the heme domain of P450BM-3 with N-Palmitoylglycine

1JPZ の概要

• エントリーDOI: 10.2210/pdb1jpz/pdb
• 関連するPDBエントリー: 1BU7 1FAG
• 分子名称: BIFUNCTIONAL P-450:NADPH-P450 REDUCTASE, PROTOPORPHYRIN IX CONTAINING FE, N-PALMITOYLGLYCINE, ... (4 entities in total)
• 機能のキーワード: protein-substrate complex, hemeprotein, oxidoreductase
• 由来する生物種: Bacillus megaterium
• 細胞内の位置: Cytoplasm (By similarity): P14779
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 109656.77

構造登録者

Haines, D.C.,Tomchick, D.R.,Machius, M.,Peterson, J.A. (登録日: 2001-08-03, 公開日: 2001-11-09, 最終更新日: 2023-08-16)

主引用文献

Haines, D.C.,Tomchick, D.R.,Machius, M.,Peterson, J.A.
Pivotal role of water in the mechanism of P450BM-3.
Biochemistry, 40:13456-13465, 2001

PubMed Abstract: Cytochrome P450s constitute a superfamily of enzymes that catalyze the oxidation of a vast number of structurally and chemically diverse hydrophobic substrates. Herein, we describe the crystal structure of a complex between the bacterial P450BM-3 and the novel substrate N-palmitoylglycine at a resolution of 1.65 A, which reveals previously unrecognizable features of active site reorganization upon substrate binding. N-palmitoylglycine binds with higher affinity than any other known substrate and reacts with a higher turnover number than palmitic acid but with unaltered regiospecificity along the fatty acid moiety. Substrate binding induces conformational changes in distinct regions of the enzyme including part of the I-helix adjacent to the active site. These changes cause the displacement by about 1 A of the pivotal water molecule that ligands the heme iron, resulting in the low-spin to high-spin conversion of the iron. The water molecule is trapped close to the heme group, which allows it to partition between the iron and the new binding site. This partitioning explains the existence of a high-spin-low-spin equilibrium after substrate binding. The close proximity of the water molecule to the heme iron indicates that it may also participate in the proton-transfer cascade that leads to heterolytic bond scission of oxygen in P450BM-3.

PubMed: 11695892
DOI: 10.1021/bi011197q

実験手法

X-RAY DIFFRACTION (1.65 Å)