title: Crystallization and preliminary X-ray crystallographic analysis of yeast NAD+-specific isocitrate dehydrogenase.
abstract: NAD+-specific isocitrate dehydrogenase (IDH; EC 1.1.1.41) is a complex allosterically regulated enzyme in the tricarboxylic acid cycle. Yeast IDH is believed to be an octamer containing four catalytic IDH2 and four regulatory IDH1 subunits. Crystals of yeast IDH have been obtained and optimized using sodium citrate, a competitive inhibitor of the enzyme, as the precipitating agent. The crystals belong to space group R3, with unit-cell parameters a = 302.0, c = 112.1 A. Diffraction data were collected to 2.9 A from a native crystal and to 4.0 A using multiwavelength anomalous diffraction (MAD) methods from an osmium derivative. Initial electron-density maps reveal large solvent channels and the molecular boundaries of the allosteric IDH multimer.
authors.affiliation: Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
authors.forename: Gang
authors.initials: G
authors.lastname: Hu
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Taylor
authors.forename: Lee
authors.initials: L
authors.lastname: McAlister-Henn
authors.forename: P John
authors.initials: PJ
authors.lastname: Hart
mesh_terms: D000495:Allosteric Site; D001665:Binding Sites; D020134:Catalytic Domain; D003460:Crystallization / Q000379:methods; D018360:Crystallography, X-Ray; D007521:Isocitrate Dehydrogenase / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008024:Ligands; D013329:Structure-Activity Relationship; D015003:Yeasts / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism
chemical_list: D008024:Ligands; D007521:Isocitrate Dehydrogenase