3CUR
Structure of a double methionine mutant of NI-FE hydrogenase
Summary for 3CUR
| Entry DOI | 10.2210/pdb3cur/pdb |
| Related | 1FRF 1YQW 1YRQ 3CUS |
| Descriptor | Periplasmic [NiFe] hydrogenase small subunit, Periplasmic [NiFe] hydrogenase large subunit, IRON/SULFUR CLUSTER, ... (10 entities in total) |
| Functional Keywords | ni-fe hydrogenase tunnel mutant, iron, iron-sulfur, metal-binding, oxidoreductase, nickel |
| Biological source | Desulfovibrio fructosovorans More |
| Cellular location | Periplasm: P18187 P18188 |
| Total number of polymer chains | 6 |
| Total formula weight | 268903.80 |
| Authors | Volbeda, A. (deposition date: 2008-04-17, release date: 2008-08-05, Last modification date: 2024-11-06) |
| Primary citation | Leroux, F.,Dementin, S.,Burlat, B.,Cournac, L.,Volbeda, A.,Champ, S.,Martin, L.,Guigliarelli, B.,Bertrand, P.,Fontecilla-Camps, J.,Rousset, M. Experimental approaches to kinetics of gas diffusion in hydrogenase Proc.Natl.Acad.Sci.Usa, 105:11188-11193, 2008 Cited by PubMed Abstract: Hydrogenases, which catalyze H(2) to H(+) conversion as part of the bioenergetic metabolism of many microorganisms, are among the metalloenzymes for which a gas-substrate tunnel has been described by using crystallography and molecular dynamics. However, the correlation between protein structure and gas-diffusion kinetics is unexplored. Here, we introduce two quantitative methods for probing the rates of diffusion within hydrogenases. One uses protein film voltammetry to resolve the kinetics of binding and release of the competitive inhibitor CO; the other is based on interpreting the yield in the isotope exchange assay. We study structurally characterized mutants of a NiFe hydrogenase, and we show that two mutations, which significantly narrow the tunnel near the entrance of the catalytic center, decrease the rates of diffusion of CO and H(2) toward and from the active site by up to 2 orders of magnitude. This proves the existence of a functional channel, which matches the hydrophobic cavity found in the crystal. However, the changes in diffusion rates do not fully correlate with the obstruction induced by the mutation and deduced from the x-ray structures. Our results demonstrate the necessity of measuring diffusion rates and emphasize the role of side-chain dynamics in determining these. PubMed: 18685111DOI: 10.1073/pnas.0803689105 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.4 Å) |
Structure validation
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