2OBI

Crystal structure of the Selenocysteine to Cysteine Mutant of human phospholipid hydroperoxide glutathione peroxidase (GPx4)

2OBI の概要

• エントリーDOI: 10.2210/pdb2obi/pdb
• 分子名称: Phospholipid hydroperoxide glutathione peroxidase (GPX4) (2 entities in total)
• 機能のキーワード: human gpx4, peroxidase, selenoprotein, thioredoxin-fold, anti-oxidatve defense system, oxidoreductase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Mitochondrion: P36969
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 20955.08

構造登録者

Scheerer, P.,Krauss, N.,Hoehne, W. (登録日: 2006-12-19, 公開日: 2007-09-18, 最終更新日: 2023-08-30)

主引用文献

Scheerer, P.,Borchert, A.,Krauss, N.,Wessner, H.,Gerth, C.,Hohne, W.,Kuhn, H.
Structural basis for catalytic activity and enzyme polymerization of phospholipid hydroperoxide glutathione peroxidase-4 (GPx4).
Biochemistry, 46:9041-9049, 2007

PubMed Abstract: Phospholipid hydroperoxide glutathione peroxidase (GPx4) is a moonlighting selenoprotein, which has been implicated in anti-oxidative defense, sperm development, and cerebral embryogenesis. Among GPx-isoforms, GPx4 is unique because of its capability to reduce complex lipid hydroperoxides and its tendency toward polymerization, but the structural basis for these properties remained unclear. To address this, we solved the crystal structure of the catalytically active U46C mutant of human GPx4 to 1.55 A resolution. X-ray data indicated a monomeric protein consisting of four alpha-helices and seven beta-strands. GPx4 lacks a surface exposed loop domain, which appears to limit the accessibility of the active site of other GPx-isoforms, and these data may explain the broad substrate specificity of GPx4. The catalytic triad (C46, Q81, and W136) is localized at a flat impression of the protein surface extending into a surface exposed patch of basic amino acids (K48, K135, and R152) that also contains polar T139. Multiple mutations of the catalytic triad indicated its functional importance. Like the wild-type enzyme, the U46C mutant exhibits a strong tendency toward protein polymerization, which was prevented by reductants. Site-directed mutagenesis suggested involvement of the catalytic C46 and surface exposed C10 and C66 in polymer formation. In GPx4 crystals, these residues contact adjacent protein monomers.

PubMed: 17630701
DOI: 10.1021/bi700840d

実験手法

X-RAY DIFFRACTION (1.55 Å)