title: Tungsten-containing formate dehydrogenase from Desulfovibrio gigas: metal identification and preliminary structural data by multi-wavelength crystallography.
abstract: The tungsten-containing formate dehydrogenase (W-FDH) isolated from Desulfovibrio gigas has been crystallized in space group P2(1), with cell parameters a = 73.8 A, b = 111.3 A, c = 156.6 A and beta = 93.7 degrees. These crystals diffract to beyond 2.0 A on a synchrotron radiation source. W-FDH is a heterodimer (92 kDa and 29 kDa subunits) and two W-FDH molecules are present in the asymmetric unit. Although a molecular replacement solution was found using the periplasmic nitrate reductase as a search model, additional phasing information was needed. A multiple-wavelength anomalous dispersion (MAD) dataset was collected at the W- and Fe-edges, at four different wavelengths. Anomalous and dispersive difference data allowed us to unambiguously identify the metal atoms bound to W-FDH as one W atom with a Se-cysteine ligand as well as one [4Fe-4S] cluster in the 92 kDa subunit, and three additional [4Fe-4S] centers in the smaller 29 kDa subunit. The D. gigas W-FDH was previously characterized based on metal analysis and spectroscopic data. One W atom was predicted to be bound to two molybdopterin guanine dinucleotide (MGD) pterin cofactors and two [4Fe-4S] centers were proposed to be present. The crystallographic data now reported reveal a selenium atom (as a Se-cysteine) coordinating to the W site, as well as two extra [4Fe-4S] clusters not anticipated before. The EPR data were re-evaluated in the light of these new results.
authors.affiliation: Departamento de Química, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2825-114 Caparica, Portugal.
authors.forename: H
authors.initials: H
authors.lastname: Raaijmakers
authors.forename: S
authors.initials: S
authors.lastname: Teixeira
authors.forename: J M
authors.initials: JM
authors.lastname: Dias
authors.forename: M J
authors.initials: MJ
authors.lastname: Almendra
authors.forename: C D
authors.initials: CD
authors.lastname: Brondino
authors.forename: I
authors.initials: I
authors.lastname: Moura
authors.forename: J J
authors.initials: JJ
authors.lastname: Moura
authors.forename: M J
authors.initials: MJ
authors.lastname: Romão
mesh_terms: D018360:Crystallography, X-Ray / Q000379:methods; D003901:Desulfovibrio / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy; D005560:Formate Dehydrogenases / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D008670:Metals / Q000032:analysis; D008958:Models, Molecular; D011487:Protein Conformation; D014414:Tungsten
chemical_list: D007506:Iron-Sulfur Proteins; D008670:Metals; D005560:Formate Dehydrogenases; D014414:Tungsten