1JPR

Mn substituted Ribonucleotide reductase R2 from E. coli oxidized by nitric oxide

1JPR の概要

• エントリーDOI: 10.2210/pdb1jpr/pdb
• 関連するPDBエントリー: 1JQC
• 分子名称: Protein R2 of Ribonucleotide reductase, MANGANESE (II) ION, MERCURY (II) ION, ... (4 entities in total)
• 機能のキーワード: radical protein, mn substituted, oxidized by no, oxidoreductase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 89881.74

構造登録者

Hogbom, M.,Andersson, M.E.,Nordlund, P. (登録日: 2001-08-03, 公開日: 2001-08-15, 最終更新日: 2024-04-03)

主引用文献

Hogbom, M.,Andersson, M.E.,Nordlund, P.
Crystal structures of oxidized dinuclear manganese centres in Mn-substituted class I ribonucleotide reductase from Escherichia coli: carboxylate shifts with implications for O2 activation and radical generation.
J.Biol.Inorg.Chem., 6:315-323, 2001

PubMed Abstract: The di-iron carboxylate proteins constitute a diverse class of non-heme iron enzymes performing a multitude of redox reactions. These reactions usually involve high-valent Fe-oxo species and are thought to be controlled by carboxylate shifts. Owing to their short lifetime, the intermediate structures have so far escaped structural characterization by X-ray crystallography. In an attempt to map the carboxylate conformations available to the protein during different redox states and different ligand environments, we have studied metal-substituted forms of the R2 protein of ribonucleotide reductase from Escherichia coli. In the present work we have solved the crystal structures of Mn-substituted R2 oxidized in two different ways. Oxidation was performed using either nitric oxide or a combination of hydrogen peroxide and hydroxylamine. The two structures are virtually identical, indicating that the oxidation states are the same, most likely a mixed-valent MnII-MnIII centre. One of the carboxylate ligands (D84) adopts a new, so far unseen, conformation, which could participate in the mechanism for radical generation in R2. E238 adopts a bridging-chelating conformation proposed to be important for proper O2 activation but not previously observed in the wild-type enzyme. Probable catalase activity was also observed during the oxidation with H2O2, indicating mechanistic similarities to the di-Mn catalases.

PubMed: 11315567
DOI: 10.1007/s007750000205

実験手法

X-RAY DIFFRACTION (1.88 Å)