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1.
Cowpea chlorotic mottle virus belongs to the brome mosaic virus group of the small spherical plant viruses. It contains 180 protein subunits, which are arranged on a T = 3 icosahedral surface lattice. The virus crystallizes in orthorhombic space group P21212 (a = 394 A?, b = 382 A?, and c = 397 A?). The unit cell contains four virus particles, while the crystallographic asymmetric unit consists of one complete virion. X-ray diffraction data from the crystals extend to nearly 3.0 Å resolution.  相似文献   

2.
Erysimum latent virus, a tymovirus, contains 180 protein subunits arranged in a T = 3 icosahedral surface lattice. A cubic crystal form (with space group P213 and a = 414 A?) and a monoclinic form (space group B2, a = 442 A?, b = 422 A?, c = 387 A?, γ = 95 °) have been observed. The asymmetric units of the two crystal forms contain one-third and one whole virus particle, respectively. Two possible packing arrangements of the virus particles in the monoclinic unit cell have been deduced from the low-angle diffraction patterns. X-ray diffraction data from the monoclinic crystals extend to at least 3·7 Å resolution.  相似文献   

3.
Tobacco ringspot virus belongs to the nepovirus group of the small spherical plant viruses. It has been suggested that the protein capsid, which displays icosahedral symmetry, consists of 240 protein subunits which are arranged on a T = 4 surface lattice. The virus crystallizes in orthorhombic space group P212121 (a = 388 A?, b = 396 A?, and c = 405 A?). The unit cell contains four virus particles while the crystallographic asymmetric unit consists of one complete virion. X-ray diffraction data from the crystals extend to at least 3.3 Å resolution.  相似文献   

4.
Lactoglobulin isolated from Italian buffalo milk has been crystallized in two different forms. Crystals of type I have been grown at pH 3.5 and belong to space group P63; the unit cell dimensions are a = b = 67 A?, c = 142 A?, and accordingly the asymmetric unit contains one dimer of molecular weight 36,000. Type II crystals, grown at pH 8.5, have only one monomer per asymmetric unit; the space group is P3121 (or enantiomorph) and the unit cell edges are: a = b = 54.4 A?, c = 113.2 A?. The crystals of the trigonal form show low radiation damage and are suitable for a structural investigation.  相似文献   

5.
Three new crystal forms of cow α-lactalbumin are described. A trigonal form in space group P3121 or P3221 has unit cell dimensions: a = b = 57.4 A?, c = 75.0 A?. A hexagonal form in space group P622 has unit cell dimensions: a = b = 94.0 A?, c = 67.1 A?. A second trigonal form grown in the presence of calcium ions belongs to space group P321 with unit cell dimensions: a = b = 93.7 A?, c = 66.9 A?. The significance of these new crystal forms to the structure determination of cow α-laetalbumin is discussed.  相似文献   

6.
Crystals of myohemerythrin   总被引:1,自引:0,他引:1  
Crystals have been grown of metazide myohemerythrin from the sipunculid Dendrostomum pyroides. The crystals are in space group P212121 and have unit cell dimensions of a = 41.6 A?, b = 80.0 A?and c = 37.8 A?. An asymmetric unit contains a single myohemerythrin molecule.  相似文献   

7.
Poliovirus contains 60 copies each of four coat protein subunits arranged on a T = 1 icosahedral surface. Crystals of the Mahoney and the Sabin strains of the type I serotype of polio have been obtained. Crystals of the Mahoney strain belong to the orthorhombic space group P21212 with a = 324 A?, b = 359 A?, c = 381 A?, contain 12 virus particle in the asymmetric unit, and diffract to at least 2.5 Å resolution. The crystals are apparently identical to those characterized by Finch & Klug (1959). Collection of three-dimensional X-ray diffraction data to 2.9 Å resolution is in progress.  相似文献   

8.
Three crystal forms of rabbit muscle creatine kinase have been grown, one of which seems suited to a high resolution X-ray diffraction study. The first form is of monoclinic space group P21 with a = 54 A?, b = 114 A?, c = 145 A?, β = 91 ° and has as the asymmetric unit two molecules of total molecular weight 160, 000. The second form, grown in the presence of mercurials, is of space group A2 with a = 52 A?, b = 165 A?, c = 237 A?, β = 91 ° and also has two molecules in the asymmetric unit. The third crystal form, grown in the presence of a high concentration of cysteine, is of apparent space group P212121, but evidence indicates that the true space group may be P21221. The dimensions of the orthorhombic unit cell are a = 47 A?, b = 86 A?, c = 125 A?, and the asymmetric unit contains a single protein subunit. Assuming the latter space group, then the creatine kinase molecule possesses a twofold axis relating two identical subunits.  相似文献   

9.
A complex between EcoRI restriction endonuclease and cognate DNA fragment, 5′-G-A-A-T-T-C C-T-T-A-A-G-5′, has been crystallized. The space group is P4212 with a = b = 183.2A?, c = 49.7A?, α = β = γ = 90 °. The unit cell contains four enzyme monomers plus two duplex DNA fragments in an asymmetric unit. High quality crystals of the enzyme alone have also been obtained.  相似文献   

10.
A complex between the complementary hexanucleotides ribo-C-A-A-A-A-G and deoxyribo-C-T-T-T-T-G has been crystallized. The space group was determined to be P21 with unit cell dimensions a = 26.9 A?, b = 50.9 A?, c = 62.0 A?; α = γ = 90 °, β = 108 °. The crystals contain both the ribo- and the deoxyribo-hexanucleotide strands in a ratio of approximately 1:1. Each asymmetric unit contains the equivalent of four hybrid molecules.  相似文献   

11.
Crystals of a relatively unspecific NAD(P)H dehydrogenase from human erythrocytes suitable for X-ray analysis have been grown. They belong to space group P41212 or its enantiomorph P43212 with unit cell dimensions: a = b = 79.3 A? and c = 38.1 A?. The asymmetric unit contains one molecule of Mr 18,000.  相似文献   

12.
Single crystals of an l-arabinose-binding protein from Escherichia coli B/r suitable for a high-resolution structural analysis have been obtained. An X-ray examination of the orthorhombic crystals shows the space group is P212121, with unit cell dimensions: a = 55.3 A?, b = 71.4 A? and c = 77.5 A?. The asymmetric unit contains one protein molecule with a molecular weight of 38,000.  相似文献   

13.
The parvalbumin IIIf of the superfast swimbladder muscle of Opsanus tau has been crystallized by a vapor diffusion technique using (NH4)2SO4 as a precipitant agent. The crystals belong to space group P21, with a unit cell a = 27.31 A?, b = 58.75 A?, c = 30.83 A? and β = 98 ° 30′, and the asymmetric unit contains one molecule. These crystals are suitable for a high resolution crystallographic investigation.  相似文献   

14.
The major form of bovine erythrocyte carbonic anhydrase has been prepared by a new method in which the conventional chloroform-ethanol treatment is replaced by chromatography on DEAE-Sephadex. Single crystals, suitable for high resolution X-ray diffraction studies, have been obtained from enzyme prepared by this method. The space group is P6122. The unit cell contains 12 enzyme molecules and has the dimensions a = b = 68 A?, c = 244 A?.  相似文献   

15.
Large hexagonal crystals of ricinus lectin, present as a major component in the seeds of Ricinus communis, have been obtained at 4 °C in the presence of polyethylene glycol 6000 by vapor diffusion against media containing acetic acid. The crystals are of space group P622, with hexagonal unit cell parameters a = b = 166 A? and c = 341 A?. The asymmetric unit contains two molecules of molecular weight 125,000. The crystals are extremely unstable, both to environmental changes and to X-irradiation, and have a solvent content of approximately 55% by volume.  相似文献   

16.
A complex of ribosomal proteins B-L8 and B-L13 from Bacillus stearothermophilus has been isolated and crystallized. The cell dimensions are a = b = 108 A?, c = 242 A? with the space group P41212 (or P43212). The asymmetric unit probably contains two complexes with a 4:1 stoichiometry of the proteins.  相似文献   

17.
The serotype B of exfoliative toxin, isolated from Staphylococcus aureus, strain TC 142, has been crystallized. The monoclinic crystals belong to space group P21, with a = 55.9 A?, b = 107.9 A?, c = 42.8 A?, and β = 90.9 °. The asymmetric unit contains two molecules of molecular weight 30,000.  相似文献   

18.
Crystals of the complex between porcine pancreatic secretory trypsin inhibitor (Kazal PSTI) and trypsinogen have been grown from magnesium sulphate solution at pH 6.7. The crystals belong to space group P212121, with unit cell edges a = 67.1 A?, b = 75.5 A?, c = 66.9 A?, and the asymmetric unit contains one complex moiety. This crystalline modification is suitable for a high-resolution crystallographic investigation.  相似文献   

19.
Crystals of crambin, a plant seed protein of molecular weight 5000, diffract X-rays strongly to the interplanar spacing limit of 0.88 Å. These diffraction data should allow a definition of atomic structure that is on a par with that typically obtained from crystals of small organic molecules. The crystals are in space group P21 and have unit cell dimensions a = 41.1 A?, b = 18.7 A?, c = 22·7 A?, and β = 90.6 °. The asymmetric unit contains one protein molecule.  相似文献   

20.
Single crystals of adenylosuccinate synthetase, an essential component of purine biosynthesis, extracted from rabbit skeletal muscle were prepared as suitable specimens for X-ray structure analysis. The crystal belongs to the space group P43212 or P41212 with unit cell dimensions a = b = 71.2 A?, c = 194.8 A?. The asymmetric unit contains one protein molecule of 54,000 molecular weight.  相似文献   

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