8POX
Crystal Structure of the C19G variant of the membrane-bound [NiFe]-Hydrogenase from Cupriavidus necator in the H2-reduced state at 1.6 A Resolution.
Summary for 8POX
| Entry DOI | 10.2210/pdb8pox/pdb |
| Related | 3RGW 4IUB 4IUC 4IUD 4TTT 5D51 5MDJ 5MDK 5MDL 7ODG 7ODH |
| Descriptor | Uptake hydrogenase large subunit, Fe4S4, Uptake hydrogenase small subunit, ... (11 entities in total) |
| Functional Keywords | [nife]-hydrogenase, hydrogenase, oxygen-tolerance, hydrogen catalysis, knallgasbacteria, proteobacteria, metalloenzyme, bimetallic, ni-fe active site, [4fe-3s], proximal cluster, aerobic hydrogen bacteria, oxidoreductase, electron transfer, metalloprotein, catalytic center, membrane, membrane-bound, oxidoreductase-oxidoreductase complex, electron relay, cubane cluster, high potential, cluster tuning, electron transport, h2-reduced |
| Biological source | Cupriavidus necator H16 More |
| Total number of polymer chains | 2 |
| Total formula weight | 104998.13 |
| Authors | |
| Primary citation | Schmidt, A.,Kalms, J.,Lorent, C.,Katz, S.,Frielingsdorf, S.,Evans, R.M.,Fritsch, J.,Siebert, E.,Teutloff, C.,Armstrong, F.A.,Zebger, I.,Lenz, O.,Scheerer, P. Stepwise conversion of the Cys 6 [4Fe-3S] to a Cys 4 [4Fe-4S] cluster and its impact on the oxygen tolerance of [NiFe]-hydrogenase. Chem Sci, 14:11105-11120, 2023 Cited by PubMed Abstract: The membrane-bound [NiFe]-hydrogenase of is a rare example of a truly O-tolerant hydrogenase. It catalyzes the oxidation of H into 2e and 2H in the presence of high O concentrations. This characteristic trait is intimately linked to the unique Cys[4Fe-3S] cluster located in the proximal position to the catalytic center and coordinated by six cysteine residues. Two of these cysteines play an essential role in redox-dependent cluster plasticity, which bestows the cofactor with the capacity to mediate two redox transitions at physiological potentials. Here, we investigated the individual roles of the two additional cysteines by replacing them individually as well as simultaneously with glycine. The crystal structures of the corresponding MBH variants revealed the presence of Cys[4Fe-4S] or Cys[4Fe-4S] clusters of different architecture. The protein X-ray crystallography results were correlated with accompanying biochemical, spectroscopic and electrochemical data. The exchanges resulted in a diminished O tolerance of all MBH variants, which was attributed to the fact that the modified proximal clusters mediated only one redox transition. The previously proposed O protection mechanism that detoxifies O to HO using four protons and four electrons supplied by the cofactor infrastructure, is extended by our results, which suggest efficient shutdown of enzyme function by formation of a hydroxy ligand in the active site that protects the enzyme from O binding under electron-deficient conditions. PubMed: 37860641DOI: 10.1039/d3sc03739h PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.6 Å) |
Structure validation
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