1frf

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spinqualitylabelsall models 1frf, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF THE NI-FE HYDROGENASE FROM DESULFOVIBRIO FRUCTOSOVORANS

Overview

The role of the high potential [3Fe-4S]1+,0 cluster of [NiFe] hydrogenase, from Desulfovibrio species located halfway between the proximal and distal, low potential [4Fe-4S]2+,1+ clusters has been investigated by using, site-directed mutagenesis. Proline 238 of Desulfovibrio fructosovorans, [NiFe] hydrogenase, which occupies the position of a potential ligand of, the lacking fourth Fe-site of the [3Fe-4S] cluster, was replaced by a, cysteine residue. The properties of the mutant enzyme were investigated in, terms of enzymatic activity, EPR, and redox properties of the iron-sulfur, centers and crystallographic structure. We have shown on the basis of both, spectroscopic and x-ray crystallographic studies that the [3Fe-4S] cluster, of D. fructosovorans hydrogenase was converted into a [4Fe-4S] center in, the P238 mutant. The [3Fe-4S] to [4Fe-4S] cluster conversion resulted in a, lowering of approximately 300 mV of the midpoint potential of the modified, cluster, whereas no significant alteration of the spectroscopic and redox, properties of the two native [4Fe-4S] clusters and the NiFe center, occurred. The significant decrease of the midpoint potential of the, intermediate Fe-S cluster had only a slight effect on the catalytic, activity of the P238C mutant as compared with the wild-type enzyme. The, implications of the results for the role of the high-potential [3Fe-4S], cluster in the intramolecular electron transfer pathway are discussed.

About this Structure

1FRF is a Protein complex structure of sequences from Desulfovibrio fructosovorans with FE, NI, MG, SF4 and F3S as ligands. Active as Ferredoxin hydrogenase, with EC number 1.12.7.2 Full crystallographic information is available from OCA.

Reference

[3Fe-4S] to [4Fe-4S] cluster conversion in Desulfovibrio fructosovorans [NiFe] hydrogenase by site-directed mutagenesis., Rousset M, Montet Y, Guigliarelli B, Forget N, Asso M, Bertrand P, Fontecilla-Camps JC, Hatchikian EC, Proc Natl Acad Sci U S A. 1998 Sep 29;95(20):11625-30. PMID:9751716

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