5NKU
Joint neutron/X-ray structure of dimeric chlorite dismutase from Cyanothece sp. PCC7425
Summary for 5NKU
| Entry DOI | 10.2210/pdb5nku/pdb |
| Descriptor | Chlorite Dismutase, PROTOPORPHYRIN IX CONTAINING FE, HYDROXIDE ION, ... (6 entities in total) |
| Functional Keywords | chlorite dismutase, cyanobacteria, heme, ferredoxin-like fold, oxidoreductase |
| Biological source | Cyanothece sp. (strain PCC 7425 / ATCC 29141) |
| Total number of polymer chains | 2 |
| Total formula weight | 45056.30 |
| Authors | Puehringer, D.,Schaffner, I.,Mlynek, G.,Obinger, C.,Djinovic-Carugo, K. (deposition date: 2017-04-03, release date: 2018-02-28, Last modification date: 2024-05-01) |
| Primary citation | 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 Cited by 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: 29142780DOI: 10.1021/acscatal.7b01749 PDB entries with the same primary citation |
| Experimental method | NEUTRON DIFFRACTION (2.35 Å) X-RAY DIFFRACTION (2 Å) |
Structure validation
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