3RGW

Crystal structure at 1.5 A resolution of an H2-reduced, O2-tolerant hydrogenase from Ralstonia eutropha unmasks a novel iron-sulfur cluster

Summary for 3RGW

• Entry DOI: 10.2210/pdb3rgw/pdb
• Descriptor: Membrane-bound hydrogenase (NIFE) large subunit HOXG, Membrane-bound hydrogenase (NIFE) small subunit HOXK, formyl[bis(hydrocyanato-1kappaC)]ironnickel(Fe-Ni), ... (8 entities in total)
• Functional Keywords: [nife] hydrogenase, high-resolution crystal structure, knallgasbacteria, proteobacteria, aerobic hydrogen bacteria, dehydrogenase, oxidoreductase, hydrogen, dihydrogen, hydrogen catalysis, metalloenzyme, metalloprotein catalytic center, nickel, iron, nickel-iron cofactor, bimetallic, ni-fe active site, iron-sulfur cluster, t-cluster, [4fe-3s] cluster, [3fe-4s] cluster, [4fe-4s] cluster, reduced state, oxygen-tolerant hydrogenase, membrane, membrane-bound, oxidoreductase-oxidoreductase complex, oxidoreductase/oxidoreductase
• Biological source: Ralstonia eutropha; More
• Cellular location: Cell membrane; Peripheral membrane protein: P31891 P31892
• Total number of polymer chains: 2
• Total formula weight: 105818.62

Authors

Scheerer, P.,Fritsch, J.,Frielingsdorf, S.,Kroschinsky, S.,Friedrich, B.,Lenz, O.,Spahn, C.M.T. (deposition date: 2011-04-10, release date: 2011-10-26, Last modification date: 2023-09-13)

Primary citation

Fritsch, J.,Scheerer, P.,Frielingsdorf, S.,Kroschinsky, S.,Friedrich, B.,Lenz, O.,Spahn, C.M.
The crystal structure of an oxygen-tolerant hydrogenase uncovers a novel iron-sulphur centre.
Nature, 479:249-252, 2011

PubMed Abstract: Hydrogenases are abundant enzymes that catalyse the reversible interconversion of H(2) into protons and electrons at high rates. Those hydrogenases maintaining their activity in the presence of O(2) are considered to be central to H(2)-based technologies, such as enzymatic fuel cells and for light-driven H(2) production. Despite comprehensive genetic, biochemical, electrochemical and spectroscopic investigations, the molecular background allowing a structural interpretation of how the catalytic centre is protected from irreversible inactivation by O(2) has remained unclear. Here we present the crystal structure of an O(2)-tolerant [NiFe]-hydrogenase from the aerobic H(2) oxidizer Ralstonia eutropha H16 at 1.5 Å resolution. The heterodimeric enzyme consists of a large subunit harbouring the catalytic centre in the H(2)-reduced state and a small subunit containing an electron relay consisting of three different iron-sulphur clusters. The cluster proximal to the active site displays an unprecedented [4Fe-3S] structure and is coordinated by six cysteines. According to the current model, this cofactor operates as an electronic switch depending on the nature of the gas molecule approaching the active site. It serves as an electron acceptor in the course of H(2) oxidation and as an electron-delivering device upon O(2) attack at the active site. This dual function is supported by the capability of the novel iron-sulphur cluster to adopt three redox states at physiological redox potentials. The second structural feature is a network of extended water cavities that may act as a channel facilitating the removal of water produced at the [NiFe] active site. These discoveries will have an impact on the design of biological and chemical H(2)-converting catalysts that are capable of cycling H(2) in air.

PubMed: 22002606
DOI: 10.1038/nature10505

Experimental method

X-RAY DIFFRACTION (1.5 Å)