1IVJ

Crystal Structure of Rat Hemeoxygenase-1 in Complex with Heme and Azide.

1IVJ の概要

• エントリーDOI: 10.2210/pdb1ivj/pdb
• 関連するPDBエントリー: 1DVE 1IRM
• 分子名称: Hemeoxygenase-1, AZIDE ION, PROTOPORPHYRIN IX CONTAINING FE, ... (4 entities in total)
• 機能のキーワード: alpha helix, di-oxygen analog complex, oxidoreductase
• 由来する生物種: Rattus norvegicus (Norway rat)
• 細胞内の位置: Microsome: P06762
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 31313.02

構造登録者

Sugishima, M.,Sakamoto, H.,Omata, Y.,Hayashi, S.,Noguchi, M.,Fukuyama, K. (登録日: 2002-03-18, 公開日: 2002-12-11, 最終更新日: 2023-10-25)

主引用文献

Sugishima, M.,Sakamoto, H.,Omata, Y.,Hayashi, S.,Noguchi, M.,Fukuyama, K.
Crystal Structure of Rat Heme Oxygenase-1 in Complex with Heme Bound to Azide. IMPLICATION FOR REGIOSPECIFIC HYDROXYLATION OF HEME AT THE alpha -MESO CARBON
J.Biol.Chem., 277:45086-45090, 2002

PubMed Abstract: Heme oxygenase (HO) catalyzes physiological heme degradation consisting of three sequential oxidation steps that use dioxygen molecules and reducing equivalents. We determined the crystal structure of rat HO-1 in complex with heme and azide (HO-heme-N(3)(-)) at 1.9-A resolution. The azide, whose terminal nitrogen atom is coordinated to the ferric heme iron, is situated nearly parallel to the heme plane, and its other end is directed toward the alpha-meso position of the heme. Based on resonance Raman spectroscopic analysis of HO-heme bound to dioxygen, this parallel coordination mode suggests that the azide is an analog of dioxygen. The azide is surrounded by residues of the distal F-helix with only the direction to the alpha-meso carbon being open. This indicates that regiospecific oxygenation of the heme is primarily caused by the steric constraint between the dioxygen bound to heme and the F-helix. The azide interacts with Asp-140, Arg-136, and Thr-135 through a hydrogen bond network involving five water molecules on the distal side of the heme. This network, also present in HO-heme, may function in dioxygen activation in the first hydroxylation step. From the orientation of azide in HO-heme-N(3)(-), the dioxygen or hydroperoxide bound to HO-heme, the active oxygen species of the first reaction, is inferred to have a similar orientation suitable for a direct attack on the alpha-meso carbon.

PubMed: 12235152
DOI: 10.1074/jbc.M207267200

実験手法

X-RAY DIFFRACTION (1.9 Å)