title: Combination of methods used in the structure solution of pyruvate:ferredoxin oxidoreductase from two crystal forms.
abstract: The structure of the homodimeric 267 kDa pyruvate:ferredoxin oxidoreductase (PFOR) of Desulfovibrio africanus was solved with data from two crystals forms, both containing two monomers per asymmetric unit. Phases were obtained from multiwavelength anomalous dispersion (MAD), solvent flattening (SF), molecular replacement (MR) using a 5 A resolution electron-density search model, multiple isomorphous replacement (MIR) and, finally, electron-density averaging (DA) procedures. It is shown how the combination of all these techniques was used to overcome problems arising from incompleteness of MAD data and weak phasing power of MIR data. A real-space refinement (RSR) procedure is described to improve MR solutions and obtain very accurate protein envelopes and non-crystallographic symmetry (NCS) transformations from 5 A resolution phase information. These were crucial for the phase extension to high resolution by DA methods.
authors.affiliation: Laboratoire de Cristallographie et de Cristallogenèse des Protéines, Institut de Biologie Structurale J.-P. Ebel CEA-CNRS, 41 avenue Jules Horowitz, 38027 Grenoble CEDEX 01, France.
authors.forename: E
authors.initials: E
authors.lastname: Chabrière
authors.forename: A
authors.initials: A
authors.lastname: Volbeda
authors.forename: J C
authors.initials: JC
authors.lastname: Fontecilla-Camps
authors.forename: M
authors.initials: M
authors.lastname: Roth
authors.forename: M H
authors.initials: MH
authors.lastname: Charon
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D003901:Desulfovibrio / Q000201:enzymology; D007658:Ketone Oxidoreductases / Q000737:chemistry*; D011487:Protein Conformation; D050743:Pyruvate Synthase; D013052:Spectrometry, X-Ray Emission
chemical_list: D001426:Bacterial Proteins; D007658:Ketone Oxidoreductases; D050743:Pyruvate Synthase