3MN0

Introducing a 2-His-1-Glu Non-Heme Iron Center into Myoglobin confers Nitric Oxide Reductase activity: Cu(II)-CN-FeBMb(-His) form

3MN0 の概要

• エントリーDOI: 10.2210/pdb3mn0/pdb
• 分子名称: Myoglobin, PROTOPORPHYRIN IX CONTAINING FE, COPPER (II) ION, ... (5 entities in total)
• 機能のキーワード: alpha helix, heme, cyanide, metal-binding, no reductase, metal binding protein
• 由来する生物種: Physeter catodon (Sperm whale)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17947.93

構造登録者

Lin, Y.-W.,Yeung, N.,Gao, Y.-G.,Miner, K.D.,Lei, L.,Robinson, H.,Lu, Y. (登録日: 2010-04-20, 公開日: 2010-08-11, 最終更新日: 2024-02-21)

主引用文献

Lin, Y.W.,Yeung, N.,Gao, Y.G.,Miner, K.D.,Lei, L.,Robinson, H.,Lu, Y.
Introducing a 2-his-1-glu nonheme iron center into myoglobin confers nitric oxide reductase activity.
J.Am.Chem.Soc., 132:9970-9972, 2010

PubMed Abstract: A conserved 2-His-1-Glu metal center, as found in natural nonheme iron-containing enzymes, was engineered into sperm whale myoglobin by replacing Leu29 and Phe43 with Glu and His, respectively (swMb L29E, F43H, H64, called Fe(B)Mb(-His)). A high resolution (1.65 A) crystal structure of Cu(II)-CN(-)-Fe(B)Mb(-His) was determined, demonstrating that the unique 2-His-1-Glu metal center was successfully created within swMb. The Fe(B)Mb(-His) can bind Cu, Fe, or Zn ions, with both Cu(I)-Fe(B)Mb(-His) and Fe(II)-Fe(B)Mb(-His) exhibiting nitric oxide reductase (NOR) activities. Cu dependent NOR activity was significantly higher than that of Fe in the same metal binding site. EPR studies showed that the reduction of NO to N(2)O catalyzed by these two enzymes resulted in different intermediates; a five-coordinate heme-NO species was observed for Cu(I)-Fe(B)Mb(-His) due to the cleavage of the proximal heme Fe-His bond, while Fe(II)-Fe(B)Mb(-His) remained six-coordinate. Therefore, both the metal ligand, Glu29, and the metal itself, Cu or Fe, play crucial roles in NOR activity. This study presents a novel protein model of NOR and provides insights into a newly discovered member of the NOR family, gNOR.

PubMed: 20586490
DOI: 10.1021/ja103516n

実験手法

X-RAY DIFFRACTION (1.65 Å)