X-ray Generator (x-ray + generator)

Distribution by Scientific Domains


Selected Abstracts


Crystal packing of the c6 -type cytochrome OmcF from Geobacter sulfurreducens is mediated by an N-terminal Strep-tag II

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2008
Peer Lukat
The putative outer membrane c -type cytochrome OmcF from Geobacter sulfurreducens contains a single haem group and shows homology to soluble cytochromes c6, a class of electron-transfer proteins that are typically found in cyanobacterial photosynthetic electron-transfer chains. OmcF was overexpressed heterologously in Escherichia coli as an N-terminal Strep-tag II fusion protein and isolated using streptactin-affinity chromatography followed by size-exclusion chromatography. The structure was solved by Fe SAD using data collected to a resolution of 1.86,Å on a rotating copper-anode X-ray generator. In the crystal, packing interactions in one dimension were exclusively mediated through the Strep-tag II sequence. The tag and linker regions were in contact with three further monomers of OmcF, leading to a well defined electron-density map for this engineered and secondary-structure-free region of the molecule. [source]


Isolation, purification and preliminary X-ray characterization of Cpn60-2 (65,kDa heat-shock protein) from Mycobacterium tuberculosis

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2002
Noam Adir
Cpn60-2 is a member of a unique family of putative molecular chaperones homologous to GroEL (Cpn60) but of unknown function and found only in Mycobacterium tuberculosis and closely related species. Cpn60-2 has mainly been studied for its strong immunogenity. Here, the purification, crystallization and preliminary crystallographic analysis of M. tuberculosis Cpn60-2 are reported. The crystals belong to space group P2, with unit-cell parameters a = 57, b = 115.5, c = 81.5,Å, , = 95.5°, and contain a dimer in the asymmetric unit. The crystals diffract to 4.0,Å using a Cu rotating-anode X-ray generator. [source]


Crystallization and preliminary X-ray diffraction studies of the putative haloalkane dehalogenase DppA from Plesiocystis pacifica SIR-I

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2010
Xenia Bogdanovi
DppA from Plesiocystis pacifica SIR-I is a putative haloalkane dehalogenase (EC 3.8.1.5) and probably catalyzes the conversion of halogenated alkanes to the corresponding alcohols. The enzyme was expressed in Escherichia coli BL21 and purified to homogeneity by ammonium sulfate precipitation and reversed-phase and ion-exchange chromatography. The DppA protein was crystallized by the vapour-diffusion method and protein crystals suitable for data collection were obtained in the orthorhombic space group P21212. The DppA crystal diffracted X-rays to 1.9,Å resolution using an in-house X-ray generator. [source]


Cloning, overexpression, purification, crystallization and preliminary X-ray diffraction analysis of an atypical two-cysteine peroxiredoxin (SAOUHSC_01822) from Staphylococcus aureus NCTC 8325

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2009
Sudipta Bhattacharyya
An atypical two-cysteine peroxidase, SAOUHSC_01822, from the virulent Staphylococcus aureus strain NCTC 8325 plays a major role in the reponse of the bacterium to oxidative stress. The protein was cloned, expressed, purified to homogeneity and crystallized. The protein was crystallized from 2,M ammonium sulfate, 0.1,M Na HEPES pH 7, 2%(v/v) PEG 400. A complete diffraction data set was collected to 2.3,Å resolution using a Rigaku MicroMax HF007 Cu,K, X-ray generator and a Rigaku R-AXIS IV++ detector. The crystals belonged to space group P21, with unit-cell parameters a = 43.50, b = 149.35, c = 73.73,Å, , = 104.4°, and contained four molecules in the asymmetric unit. [source]


Crystallization and preliminary X-ray characterization of aminopeptidase N from Escherichia coli

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2006
Yuko Onohara
A recombinant form of aminopeptidase N (molecular weight 99,kDa) from Escherichia coli was crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitating agent. The crystals belong to the hexagonal space group P3121, with unit-cell parameters a = b = 120.5, c = 171.0,Å. The crystals are most likely to contain one molecule in the asymmetric unit, with a VM value of 3.62,Å3,Da,1. Diffraction data were collected to 2.0,Å resolution using Cu,K, radiation from a rotating-anode X-ray generator. [source]


Crystallization and preliminary X-ray analysis of a novel Kunitz-type kallikrein inhibitor from Bauhinia bauhinioides

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 10 2005
Marcos Vicente de A. S. Navarro
A Kunitz-type protease inhibitor (BbKI) found in Bauhinia bauhinioides seeds has been overexpressed in Escherichia coli and crystallized at 293,K using PEG 4000 as the precipitant. X-ray diffraction data have been collected to 1.87,Å resolution using an in-house X-ray generator. The crystals of the recombinant protein (rBbKI) belong to the orthorhombic space group P212121, with unit-cell parameters a = 46.70, b = 64.14, c = 59.24,Å. Calculation of the Matthews coefficient suggests the presence of one monomer of rBbKI in the asymmetric unit, with a corresponding solvent content of 51% (VM = 2.5,Å3,Da,1). Iodinated crystals were prepared and a derivative data set was also collected at 2.1,Å resolution. Crystals soaked for a few seconds in a cryogenic solution containing 0.5,M NaI were found to be reasonably isomorphous to the native crystals. Furthermore, the presence of iodide anions could be confirmed in the NaI-derivatized crystal. Data sets from native and derivative crystals are being evaluated for use in crystal structure determination by means of the SIRAS (single isomorphous replacement with anomalous scattering) method. [source]