1IYN

Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights for its instability

1IYN の概要

• エントリーDOI: 10.2210/pdb1iyn/pdb
• 分子名称: Chloroplastic ascorbate peroxidase, SODIUM ION, PROTOPORPHYRIN IX CONTAINING FE, ... (4 entities in total)
• 機能のキーワード: ascorbate, peroxidase, hydrogen peroxide, tobacco plant, stromal ascorbate peroxidase, oxidoreductase
• 由来する生物種: Nicotiana tabacum (common tobacco)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 32944.63

構造登録者

Wada, K.,Tada, T.,Nakamura, Y. (登録日: 2002-09-03, 公開日: 2003-09-03, 最終更新日: 2023-10-25)

主引用文献

Wada, K.,Tada, T.,Nakamura, Y.,Ishikawa, T.,Yabuta, Y.,Yoshimura, K.,Shigeoka, S.,Nishimura, K.
Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights into its instability
J.BIOCHEM.(TOKYO), 134:239-244, 2003

PubMed Abstract: Ascorbate peroxidase (APX) is a heme-containing protein that plays a central role in scavenging H(2)O(2) in higher plants. The structure of stromal APX (sAPX) was determined at 1.6 A to an R-factor of 19.1% and an R-free-factor of 22.3%. The electrostatic potential of the gamma-channel that connects the molecular surface of sAPX to the gamma-edge of heme was more positive than that of cytosolic APX (cAPX) from pea, so sAPX might bind more easily with ascorbate than cAPX. The overall structure of sAPX was similar to those of cAPX from pea and cytochrome c peroxidase (CCP) from yeast, with a substantial difference in a loop structure located in the vicinity of the heme. The side chain of Arg169 in sAPX corresponding to His169 in cAPX and His181 in CCP extended in the opposite direction from the heme, forming two hydrogen bonds with carbonyl groups in the loop structure. The rapid inactivation of sAPX might be due to the characteristic conformation of Arg169 owing to the loop structure of sAPX.

PubMed: 12966073
DOI: 10.1093/jb/mvg136

実験手法

X-RAY DIFFRACTION (1.6 Å)