title: High-resolution crystals of methionine aminopeptidase from Pyrococcus furiosus obtained by water-mediated transformation.
abstract: The monoclinic crystal form of methionine amino-peptidase from Pyrococcus furiosus (MAP-Pfu) has been crystallized from four different conditions. Native crystals belong to space group P2(1) with typical unit-cell dimensions a = 53.4, b = 85.1, c = 72.7 A, beta = 107.7 degrees and diffract to 2.9-4.5 A resolution. However, there is a problem of nonisomorphism among the crystals. Water-mediated transformation to low-humidity form occurs by reduction of the relative humidity of crystal environment to 79%. The unit-cell dimensions of transformed crystals are a = 51.9, b = 83.3, c = 70.3 A, beta = 105.9 degrees, and the calculated solvent content is 3.9% less than in original crystals. Transformation to low-humidity form is accompanied by 1.7 times reduction of overall temperature factors, extension of diffraction resolution up to 1.75 A, without change or reduction of crystal mosaicity, and improvement in stability to X-ray radiation. The water-mediated transformation also appears to relieve the problem of nonisomorphism among the original MAP-Pfu crystals.
authors.affiliation: Institute for Protein Research, Osaka University, Japan.
authors.forename: T H
authors.initials: TH
authors.lastname: Tahirov
authors.forename: H
authors.initials: H
authors.lastname: Oki
authors.forename: T
authors.initials: T
authors.lastname: Tsukihara
authors.forename: K
authors.initials: K
authors.lastname: Ogasahara
authors.forename: K
authors.initials: K
authors.lastname: Yutani
authors.forename: C P
authors.initials: CP
authors.lastname: Libeu
authors.forename: Y
authors.initials: Y
authors.lastname: Izu
authors.forename: S
authors.initials: S
authors.lastname: Tsunasawa
authors.forename: I
authors.initials: I
authors.lastname: Kato
mesh_terms: D000626:Aminopeptidases / Q000235:genetics / Q000302:isolation & purification*; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics; D063208:Methionyl Aminopeptidases; D019711:Pyrococcus / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification; D014867:Water
chemical_list: D011994:Recombinant Proteins; D014867:Water; D000626:Aminopeptidases; D063208:Methionyl Aminopeptidases