1XK0

Crystal Structures of the G139A, G139A-NO and G143H Mutants of Human Heme Oxygenase-1

1XK0 の概要

• エントリーDOI: 10.2210/pdb1xk0/pdb
• 関連するPDBエントリー: 1XJZ 1XK1 1XK2 1XK3
• 分子名称: Heme oxygenase 1, PROTOPORPHYRIN IX CONTAINING FE, NITRIC OXIDE, ... (4 entities in total)
• 機能のキーワード: heme, heme degredation, oxidoreductase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Microsome: P09601
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 55032.10

構造登録者

Lad, L.,Koshkin, A.,Ortiz de Montellano, P.R.,Poulos, T.L. (登録日: 2004-09-26, 公開日: 2005-12-06, 最終更新日: 2024-02-14)

主引用文献

Lad, L.,Koshkin, A.,Ortiz de Montellano, P.R.,Poulos, T.L.
Crystal structures of the G139A, G139A-NO and G143H mutants of human heme oxygenase-1. A finely tuned hydrogen-bonding network controls oxygenase versus peroxidase activity.
J.Biol.Inorg.Chem., 10:138-146, 2005

PubMed Abstract: Conserved glycines, Gly139 and Gly143, in the distal helix of human heme oxygenase-1 (HO-1) provide the flexibility required for the opening and closing of the heme active site for substrate binding and product dissociation during HO-1 catalysis. Earlier mutagenesis work on human HO-1 showed that replacement of either Gly139 or Gly143 suppresses heme oxygenase activity and, in the case of the Gly139 mutants, increases peroxidase activity (Liu et al. in J. Biol. Chem. 275:34501, 2000). To further investigate the role of the conserved distal helix glycines, we have determined the crystal structures of the human HO-1 G139A mutant, the G139A mutant in a complex with NO, and the G143H mutant at 1.88, 2.18 and 2.08 A, respectively. The results confirm that fine tuning of the previously noted active-site hydrogen-bonding network is critical in determining whether heme oxygenase or peroxidase activity is observed.

PubMed: 15690204
DOI: 10.1007/s00775-004-0620-6

実験手法

X-RAY DIFFRACTION (2.18 Å)