title: Expression, purification and crystallization of a functional core of the voltage-dependent calcium channel beta subunit.
abstract: Two versions of the functional core of the rabbit voltage-dependent calcium channel beta2a subunit were expressed in Escherichia coli. These proteins were purified to homogeneity and screened for crystallization. Crystallization conditions were refined using the hanging-drop vapour-diffusion method and two crystal forms were pursued. Crystal form I is represented by thick rods with tetragonal symmetry, unit-cell parameters a = b = 75, c = 165 A and a diffraction limit of 3.4 A which were obtained using ammonium sulfate as a precipitant. Crystal form II gives rise to plates with orthorhombic symmetry, unit-cell parameters a = 35, b = 75, c = 165 A and a diffraction limit of 2.3 A which were grown using polyethylene glycol 20K as a precipitant.
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel.
authors.forename: Yarden
authors.initials: Y
authors.lastname: Opatowsky
authors.forename: Orna
authors.initials: O
authors.lastname: Chomsky-Hecht
authors.forename: Joel A
authors.initials: JA
authors.lastname: Hirsch
mesh_terms: D015220:Calcium Channels / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D003460:Crystallization; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D015220:Calcium Channels; D021122:Protein Subunits