7CKA

The structure of Glycine max (Soybean) Heme oxygenase 1

7CKA の概要

• エントリーDOI: 10.2210/pdb7cka/pdb
• 分子名称: Heme oxygenase 1, CITRIC ACID, PROTOPORPHYRIN IX CONTAINING FE, ... (4 entities in total)
• 機能のキーワード: metal binding protein, oxidoreductase
• 由来する生物種: Glycine max (Soybean)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 26930.28

構造登録者

Tohda, R.,Tanaka, H.,Kurisu, G. (登録日: 2020-07-16, 公開日: 2020-12-30, 最終更新日: 2024-03-27)

主引用文献

Tohda, R.,Tanaka, H.,Mutoh, R.,Zhang, X.,Lee, Y.H.,Konuma, T.,Ikegami, T.,Migita, C.T.,Kurisu, G.
Crystal structure of higher plant heme oxygenase-1 and its mechanism of interaction with ferredoxin.
J.Biol.Chem., 296:100217-100217, 2020

PubMed Abstract: Heme oxygenase (HO) converts heme to carbon monoxide, biliverdin, and free iron, products that are essential in cellular redox signaling and iron recycling. In higher plants, HO is also involved in the biosynthesis of photoreceptor pigment precursors. Despite many common enzymatic reactions, the amino acid sequence identity between plant-type and other HOs is exceptionally low (∼19.5%), and amino acids that are catalytically important in mammalian HO are not conserved in plant-type HOs. Structural characterization of plant-type HO is limited to spectroscopic characterization by electron spin resonance, and it remains unclear how the structure of plant-type HO differs from that of other HOs. Here, we have solved the crystal structure of Glycine max (soybean) HO-1 (GmHO-1) at a resolution of 1.06 Å and carried out the isothermal titration calorimetry measurements and NMR spectroscopic studies of its interaction with ferredoxin, the plant-specific electron donor. The high-resolution X-ray structure of GmHO-1 reveals several novel structural components: an additional irregularly structured region, a new water tunnel from the active site to the surface, and a hydrogen-bonding network unique to plant-type HOs. Structurally important features in other HOs, such as His ligation to the bound heme, are conserved in GmHO-1. Based on combined data from X-ray crystallography, isothermal titration calorimetry, and NMR measurements, we propose the evolutionary fine-tuning of plant-type HOs for ferredoxin dependency in order to allow adaptation to dynamic pH changes on the stroma side of the thylakoid membrane in chloroplast without losing enzymatic activity under conditions of fluctuating light.

PubMed: 33839679
DOI: 10.1074/jbc.RA120.016271

実験手法

X-RAY DIFFRACTION (1.06 Å)