4IUD

Crystal structure of an O2-tolerant [NiFe]-hydrogenase from Ralstonia eutropha in its as-isolated form with ascorbate - partly reduced state

Summary for 4IUD

• Entry DOI: 10.2210/pdb4iud/pdb
• Related: 4IUB 4IUC
• Descriptor: Uptake hydrogenase large subunit, Uptake hydrogenase small subunit, NI-FE OXIDIZED ACTIVE CENTER, ... (9 entities in total)
• Functional Keywords: [nife] hydrogenase, knallgas bacteria, proteobacteria, aerobic hydrogen bacteria, hydrogen catalysis, metalloenzyme, metalloprotein catalytic center, nickel-iron cofactor, bimetallic, ni-fe active site, iron-sulfur cluster, [4fe-3s] cluster, [3fe-4s] cluster, [4fe-4s] cluster, reduced state, oxidized state, oxygen-tolerant hydrogenase, membrane-bound, oxidoreductase
• Biological source: Ralstonia eutropha; More
• Cellular location: Cell membrane; Peripheral membrane protein: P31891 P31892
• Total number of polymer chains: 2
• Total formula weight: 105901.06

Authors

Hammer, M.,Schmidt, A.,Frielingsdorf, S.,Fritsch, J.,Lenz, O.,Scheerer, P. (deposition date: 2013-01-20, release date: 2014-04-02, Last modification date: 2024-11-27)

Primary citation

Frielingsdorf, S.,Fritsch, J.,Schmidt, A.,Hammer, M.,Lowenstein, J.,Siebert, E.,Pelmenschikov, V.,Jaenicke, T.,Kalms, J.,Rippers, Y.,Lendzian, F.,Zebger, I.,Teutloff, C.,Kaupp, M.,Bittl, R.,Hildebrandt, P.,Friedrich, B.,Lenz, O.,Scheerer, P.
Reversible [4Fe-3S] cluster morphing in an O2-tolerant [NiFe] hydrogenase.
Nat.Chem.Biol., 10:378-385, 2014

PubMed Abstract: Hydrogenases catalyze the reversible oxidation of H(2) into protons and electrons and are usually readily inactivated by O(2). However, a subgroup of the [NiFe] hydrogenases, including the membrane-bound [NiFe] hydrogenase from Ralstonia eutropha, has evolved remarkable tolerance toward O(2) that enables their host organisms to utilize H(2) as an energy source at high O(2). This feature is crucially based on a unique six cysteine-coordinated [4Fe-3S] cluster located close to the catalytic center, whose properties were investigated in this study using a multidisciplinary approach. The [4Fe-3S] cluster undergoes redox-dependent reversible transformations, namely iron swapping between a sulfide and a peptide amide N. Moreover, our investigations unraveled the redox-dependent and reversible occurence of an oxygen ligand located at a different iron. This ligand is hydrogen bonded to a conserved histidine that is essential for H(2) oxidation at high O(2). We propose that these transformations, reminiscent of those of the P-cluster of nitrogenase, enable the consecutive transfer of two electrons within a physiological potential range.

PubMed: 24705592
DOI: 10.1038/nchembio.1500

Experimental method

X-RAY DIFFRACTION (1.45 Å)