title: Crystallization and preliminary x-ray diffraction studies on the conserved GTPase domain of the signal recognition particle from Acidianus ambivalens.
abstract: The signal recognition particle (SRP) of bacteria consists of only one protein, known as Ffh or the SRP54 homologue, which forms a complex with 4.5S RNA. It also binds to signal peptides and contains a GTPase which displays interesting differences to Ras GTPases. The conserved NG-domain of Ffh from the archaebacterium Acidianus ambivalens was cloned and overexpressed with a C-terminal His tag in Escherichia coli. Crystallization experiments of the native protein as well as of the Thr112Ala mutant, which is deficient in GTP hydrolysis, resulted in crystals suitable for X-ray diffraction. The crystals belong to the orthorhombic space group C222(1), with unit-cell parameters a = 64.5, b = 128.3, c = 72.0 A. At cryogenic temperatures, the crystals diffracted to a resolution limit of 2.8 A using a rotating-anode generator and contain one molecule per asymmetric unit. A native data set has been collected using synchrotron radiation to around 2.0 A resolution. Selenomethionine protein was produced; its crystals diffract in-house to about 2.8 A resolution.
authors.affiliation: European Molecular Biology Laboratory, Structural Biology Programme, Postfach 10.2209, D--69017 Heidelberg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Montoya
authors.forename: K
authors.initials: K
authors.lastname: te Kaat
authors.forename: R
authors.initials: R
authors.lastname: Moll
authors.forename: G
authors.initials: G
authors.lastname: Schäfer
authors.forename: I
authors.initials: I
authors.lastname: Sinning
mesh_terms: D001105:Archaea; D019843:Archaeal Proteins / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D003460:Crystallization; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D020558:GTP Phosphohydrolases / Q000737:chemistry*; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D016601:RNA-Binding Proteins / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D012645:Selenomethionine / Q000737:chemistry; D051140:Selenoproteins; D018271:Signal Recognition Particle / Q000737:chemistry* / Q000235:genetics; D017356:Synchrotrons; D014961:X-Ray Diffraction
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C082931:Ffh protein, E coli; D010446:Peptide Fragments; D011506:Proteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D051140:Selenoproteins; D018271:Signal Recognition Particle; D012645:Selenomethionine; D020558:GTP Phosphohydrolases