7OU9

Crystal structure of dimeric chlorite dismutase variant Q74E (CCld Q74E) from Cyanothece sp. PCC7425 in complex with nitrite

7OU9 の概要

• エントリーDOI: 10.2210/pdb7ou9/pdb
• 関連するPDBエントリー: 7OU5 7OU7
• 分子名称: Chlorite dismutase, PROTOPORPHYRIN IX CONTAINING FE, NITRITE ION, ... (7 entities in total)
• 機能のキーワード: chlorite dismutase, nitrite, oxidoreductase
• 由来する生物種: Cyanothece sp. (strain PCC 7425 / ATCC 29141)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 45327.04

構造登録者

Schmidt, D.,Mlynek, G.,Djinovic-Carugo, K.,Obinger, C. (登録日: 2021-06-11, 公開日: 2021-12-22, 最終更新日: 2024-01-31)

主引用文献

Serra, I.,Schmidt, D.,Pfanzagl, V.,Mlynek, G.,Hofbauer, S.,Djinovic-Carugo, K.,Furtmuller, P.G.,Garcia-Rubio, I.,Van Doorslaer, S.,Obinger, C.
Impact of the dynamics of the catalytic arginine on nitrite and chlorite binding by dimeric chlorite dismutase.
J.Inorg.Biochem., 227:111689-111689, 2021

PubMed Abstract: Chlorite dismutases (Clds) are heme b containing oxidoreductases able to decompose chlorite to chloride and molecular oxygen. This work analyses the impact of the distal, flexible and catalytic arginine on the binding of anionic angulate ligands like nitrite and the substrate chlorite. Dimeric Cld from Cyanothece sp. PCC7425 was used as a model enzyme. We have investigated wild-type CCld having the distal catalytic R127 hydrogen-bonded to glutamine Q74 and variants with R127 (i) being arrested in a salt-bridge with a glutamate (Q74E), (ii) being fully flexible (Q74V) or (iii) substituted by either alanine (R127A) or lysine (R127K). We present the electronic and spectral signatures of the high-spin ferric proteins and the corresponding low-spin nitrite complexes elucidated by UV-visible, circular dichroism and electron paramagnetic resonance spectroscopies. Furthermore, we demonstrate the impact of the dynamics of R127 on the thermal stability of the respective nitrite adducts and present the X-ray crystal structures of the nitrite complexes of wild-type CCld and the variants Q74V, Q74E and R127A. In addition, the molecular dynamics (MD) and the binding modi of nitrite and chlorite to the ferric wild-type enzyme and the mutant proteins and the interaction of the oxoanions with R127 have been analysed by MD simulations. The findings are discussed with respect to the role(s) of R127 in ligand and chlorite binding and substrate degradation.

PubMed: 34922158
DOI: 10.1016/j.jinorgbio.2021.111689

実験手法

X-RAY DIFFRACTION (2.42 Å)