title: Analysis of the effect of microgravity on protein crystal quality: the case of a myoglobin triple mutant.
abstract: Crystals of the Met derivative of the sperm whale myoglobin triple mutant Mb-YQR [L(B10)Y, H(E7)Q and T(E10)R] were grown under microgravity conditions and on earth by vapour diffusion. A comparison of crystal quality after complete data collection and processing shows how microgravity-grown crystals diffract to better resolution and lead to considerably improved statistics for X-ray diffraction data compared with crystals grown on earth under the same conditions. The same set of experiments was reproduced on two different Spacelab missions (ISS 6A and ISS 8A) in 2001 and 2002. The structure of this mutant myoglobin, refined using data collected at ELETTRA (Trieste, Italy) from both kinds of crystals, shows that X-ray diffraction from microgravity-grown crystals leads to better defined electron-density maps as well as improved geometrical quality of the refined model. Improvement of the stereochemical parameters of a protein structure is fundamental to quantitative analysis of its function and dynamics and hence to thorough understanding of the molecular mechanisms of action.
authors.affiliation: Dipartimento di Scienze Biochimiche and CNR Istituto di Biologia e Patologia Molecolari, Universita di Roma La Sapienza, P.le A. Moro 5, 00185 Rome, Italy.
authors.forename: Adriana E
authors.initials: AE
authors.lastname: Miele
authors.forename: Luca
authors.initials: L
authors.lastname: Federici
authors.forename: Giuliano
authors.initials: G
authors.lastname: Sciara
authors.forename: Federica
authors.initials: F
authors.lastname: Draghi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Brunori
authors.forename: Beatrice
authors.initials: B
authors.lastname: Vallone
mesh_terms: D003460:Crystallization; D004583:Electrons; D006418:Heme / Q000737:chemistry; D006801:Humans; D009154:Mutation; D009211:Myoglobin / Q000737:chemistry* / Q000235:genetics; D010084:Oxidation-Reduction; D013026:Space Flight; D014893:Weightlessness; D014961:X-Ray Diffraction
chemical_list: D009211:Myoglobin; D006418:Heme