5K90

Crystal structure of dimeric chlorite dismutase from Cyanothece sp. PCC7425 in complex with isothiocyanate

5K90 の概要

• エントリーDOI: 10.2210/pdb5k90/pdb
• 分子名称: Chlorite dismutase, isothiocyanate, PROTOPORPHYRIN IX CONTAINING FE, ... (7 entities in total)
• 機能のキーワード: chlorite dismutase, cyanobacteria, heme, ferredoxin-like fold, 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: 4
• 化学式量合計: 91071.11

構造登録者

Puehringer, D.,Schaffner, I.,Mlynek, G.,Obinger, C.,Djinovic-Carugo, K. (登録日: 2016-05-31, 公開日: 2017-06-21, 最終更新日: 2024-05-08)

主引用文献

Schaffner, I.,Mlynek, G.,Flego, N.,Puhringer, D.,Libiseller-Egger, J.,Coates, L.,Hofbauer, S.,Bellei, M.,Furtmuller, P.G.,Battistuzzi, G.,Smulevich, G.,Djinovic-Carugo, K.,Obinger, C.
Molecular Mechanism of Enzymatic Chlorite Detoxification: Insights from Structural and Kinetic Studies.
ACS Catal, 7:7962-7976, 2017

PubMed Abstract: The heme enzyme chlorite dismutase (Cld) catalyzes the degradation of chlorite to chloride and dioxygen. Although structure and steady-state kinetics of Clds have been elucidated, many questions remain (e.g., the mechanism of chlorite cleavage and the pH dependence of the reaction). Here, we present high-resolution X-ray crystal structures of a dimeric Cld at pH 6.5 and 8.5, its fluoride and isothiocyanate complexes and the neutron structure at pH 9.0 together with the pH dependence of the Fe(III)/Fe(II) couple, and the UV-vis and resonance Raman spectral features. We demonstrate that the distal Arg127 cannot act as proton acceptor and is fully ionized even at pH 9.0 ruling out its proposed role in dictating the pH dependence of chlorite degradation. Stopped-flow studies show that (i) Compound I and hypochlorite do not recombine and (ii) Compound II is the immediately formed redox intermediate that dominates during turnover. Homolytic cleavage of chlorite is proposed.

PubMed: 29142780
DOI: 10.1021/acscatal.7b01749

実験手法

X-RAY DIFFRACTION (1.28 Å)