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1.
Conditions have been established for the crystallization of tyrosyl-transfer RNA synthetase from Bacillus stearothermophilus at room temperature. The crystals are extremely well-ordered, exhibiting diffraction spots out to at least 2.7 Å, and can be grown to a convenient size for X-ray crystallographic analysis. The crystals are trigonal with a space group P3121, the unit cell having dimensions of a = 64.4 A? and c = 238 A?; the crystallographic asymmetric unit is probably one subunit of the dimeric (2 × 45,000, mol. wt) enzyme. The enzyme crystals are extremely stable and exhibit good resistance to radiation damage. This amino-acyl-tRNA synthetase appears to be amenable to complete structure determination by X-ray crystallography.  相似文献   

2.
Pseudomonas aeruginosa cytochrome oxidase (nitrite reductase, cytochrome cd) has been crystallized in space group P21212 with cell dimensions a = 122.8 A?, b = 87.2 A?, c = 73.4 A?. Density measurements suggest that the asymmetric unit contains one 63,000 molecular weight subunit of the dimeric molecule. Crystal data agree well with electron microscopy of single molecules. The X-ray pattern extends beyond 2.5 Å resolution, and structure analysis is in progress.  相似文献   

3.
Purification and crystallisation procedures are reported for azurin and cytochrome c′ from Alcaligenes denitrificans and Alcaligenes sp. NCIB 11015. The azurin crystals from A. denitrificans are suitable for high-resolution X-ray structure analysis. They are orthorhombic, space group C2221 (with marked tetragonal pseudo-symmetry), cell dimensions a = 75.0 A?, b = 74.1 A?, c = 99.5 A?, with two molecules per asymmetric unit. The cytochrome c′ crystals from both species are hexagonal, space group P6122 (or P6522), cell dimensions a = b = 54.7 A?, c ~ 185 A?, γ = 120 °, with one subunit (molecular weight 14,000) in the asymmetric unit.  相似文献   

4.
Octahedral shaped crystals of about 1 mm were grown from catalase of Micrococcus luteus. The space group was determined as P422121 with a = b = 106.6 A? and c = 106.3 A?. In contrast to mammalian catalase, the bacterial catalase contains only one subunit per asymmetric unit. This proves that the four subunits of bacterial catalase are identical.  相似文献   

5.
The Mn superoxide dismutase from Escherichia coli has been obtained in three crystal forms: (I) from 68% saturated (NH4)2SO4, space group P222 or P2221, a = 47 A?, b = 103 A?, c = 47.5 A?, with one subunit per asymmetric unit; (II) from 50% polyethylene glycol 6000, space group C2221 (with approx. P41212 symmetry), a = 101 A?, b = 108 A?, c = 180 A?, with four subunits (2 molecules) per asymmetric unit; (III) from 52% polyethylene glycol with a different method of preparing the enzyme solution, space group P21212, a = 47 A?, b = 51 A?, c = 188 A?, with two subunits per asymmetric unit.The yeast mitochondrial Mn superoxide dismutase has yielded the same crystal form both from 30% 2-methyl-2,4-pentane diol and from 23% polyethylene glycol 6000: space group P212121, a = 63 A?, b = 115 A?, c = 125 A?, with four subunits (one molecule) per asymmetric unit.A full X-ray crystallographic study of at least one of these enzymes is planned.  相似文献   

6.
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   

7.
Wheat germ agglutinin crystallizes in two monoclinic space groups, P21 and C2, under identical crystallization conditions. Unit cell dimensions are a = 73.8 A?, b = 51.2 A?, c = 90.8 A?, γ = 90 ° for P21; a = 51.31 A?, b = 73.35 A?, c = 91.45 A?, β = 97.75 ° for C2, both with eight subunit molecules in the unit cell. The C2 crystals were chosen as suitable for investigating the three-dimensional structure to high resolution, because of their smaller asymmetric unit (containing the dimer), and also because they display better diffraction patterns.  相似文献   

8.
Levansucrase, an exocellular enzyme, has been isolated from a high producer mutant, the BS5C4 constitutive strain, of Bacillus subtilis. Three crystalline forms have been obtained, all three belonging to the orthorhombic space group P212121. The most suitable form for a three-dimensional structure investigation has cell dimensions, a = 68 A?, b = 125 A?, c = 54 A?. There is one molecule in the asymmetric unit.  相似文献   

9.
Uteroglobin, which is a progesterone-binding protein of the rabbit uterine secretion, has been crystallized and subjected to X-ray diffraction analysis. Two crystalline forms have been observed: a triclinic one (P1, Z = 2, a = 36.36 (4) A?, b = 37.40 (4) A?, c = 53.28 (4) A?, α = 104.6 (1) °, β = 97.0 (1) °, γ = 111.3(1) °); and an orthorhombic one for which the cell is C-centred with a = 50.86 (5)A?, b = 52.22 (5)A?, c = 47.28 (5) A?, space group C2221, Z = 4. Three isomorphous derivatives have been obtained. The crystals appear suitable for detailed study of the three-dimensional structure of the protein.  相似文献   

10.
Crystals of histidinol dehydrogenase (EC 1.1.1.23) from Salmonella typhimurium have been obtained in large size suitable for single crystal X-ray studies. The following crystal data were obtained on examination of a number of X-ray precession photographs; crystal system monoclinic, a = 149.6 A?, b = 88.9 A?, c = 105.6 A?, β = 124.5 °, space group C2. The density of the crystal measured by flotation in bromobenzene/xylene mixture is 1.186 g/cm3. There is one dimer molecule of molecular weight 80,000 in one crystallographically asymmetric unit.  相似文献   

11.
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   

12.
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   

13.
Crystals of baboon α-lactalbumin suitable for structure analysis at high resolution have been obtained. They have cell dimensions a = 35.5 A?, b = 69.1 A?, c = 46.1 A?, space group P21212 and contain one molecule of α-lactalbumin per asymmetric unit.  相似文献   

14.
A “naturally occurring” human κI VL dimer, designated Wat, has been isolated and crystallized. Protein Wat consists of two non-covalently bound monomers, each having a molecular weight of ~ 11,500. The monomer subunit is composed of an entire variable region light chain (VL) domain closely homologous to that of the κI Bence Jones protein Roy (Hilschmann &; Craig, 1965) as evidenced from amino acid composition, tryptic peptide map, and sequence analysis. Immunochemical studies substantiated that protein Wat is of the κ chain subgroup κI and lacks the isotypic and allotypic antigenic determinants associated with the κ constant region light chain domain. Two types of crystals of VL dimer Wat were obtained from ammonium sulfate or polyethylene glycol solutions. The type I crystals have unit cell dimensions of a = b = 82.6 A?, c = 60.3 A?, and the space group is hexagonal P62 or P64. The asymmetric unit consists of one VL dimer; the fractional volume of unit cell occupied by solvent is 0.51. The unit cell dimensions of the type II crystals are a = b = 1,08.3 A?, c = 108.8 A?; the space group is hexagonal P6122 or P6522. Three variable domains constitute the asymmetric unit of the type II crystals; the fractional value of the solvent (0.52) is compatible with the value obtained for the type I crystals.  相似文献   

15.
Crystals of calotropin DI (Mr 23,400), have been prepared by microdialysis against 5% (w/v) polyethylene glycol 20,000 in water, pH 7.0. They have orthorhombic space group P212121 with cell parameters a = 57.5 A?, b = 86.2 A?, c = 40.3 A?. Crystals of calotropin DII (Mr 24,000), prepared by the same technique against 5% (w/v) polyethylene glycol 20,000 in phosphate buffer of low ionic strength, pH 7.0, display monoclinic space group C2 with cell parameters a = 135.8 A?, b = 32.0 A?, c = 47.7 A?, β = 103.80 °. In both cases, there is only one molecule in the asymmetric unit.  相似文献   

16.
Crystals of mitogenic lectin from pea seeds (Pisum sativum) have been grown. The crystals are in space group P212121 with unit cell dimensions: a = 51.0 ± 0.2 A?, b = 617 ± 0.2 A?, c = 137.6 ± 0.5 A?. The asymmetric unit has one protein molecule.  相似文献   

17.
Cytochrome c7, a low potential, three heme-containing protein (molecular weight 9800) was isolated from Desulfuromonas acetoxidans and crystallized from polyethylene glycol solutions. The crystals belong to the orthorhombic space group P212121, with unit-cell dimensions a = 44·10 A?, b = 37·55 A? and c = 45·08 A? and have one molecule of protein per asymmetric unit.  相似文献   

18.
Two crystal forms of lysozyme from the egg white of the embden goose (Anser anser) have been obtained, both of which are suitable for X-ray diffraction analysis. The monoclinic form has space group P21 with cell dimensions a = 38.3 A?, b = 65.7 A?, c = 45.2 a?, β = 116 ° and the triclinic form (space group P1) has cell dimensions of a = 39.9 A?, b = 42.2 A?, c = 57.9 A? and α = 98.8 °, β = 102.5 °, γ = 90.5 °.  相似文献   

19.
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   

20.
Binding of a simian virus 40 T antigen-related protein to DNA   总被引:90,自引:0,他引:90  
Crystals of the periplasmic galactose-binding protein of Salmonella typhimurium have been subjected to X-ray analysis. The crystals grow as elongated rectangular prisms, with the symmetry of space group C2. Unit cell dimensions are a = 119·7 A?, b = 37·2 A?, c = 80·1 A?, and β = 123·4. There is one protein molecule of molecular weight 33,000 per asymmetric unit.  相似文献   

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