Tyrocidine A: crystal growth and preliminary x-ray diffraction data.

Tyrocidine A was crystallized from 2-methyl-2,4-pentanediol and water, or methanol, to yield crystals that are large enough for X-ray diffraction studies. Four crystals were examined; three were in equilibrium with mother liquor and the fourth was air-dried. They belong to the rhombohedral space group R32. Parameters of the hexagonal cell of the fully solvated crystals vary slightly and are approximately $\text{a = 34}\text{A}\text{?}\text{and}\text{c = 50}\text{A}\text{?}$. The asymmetric unit consists of one molecule of tyrocidine and several molecules of 2-methyl-2,4-pentanediol. Air-dried crystals appear to contain about half the number of solvent molecules. Three-dimensional X-ray diffraction data showing a maximum resolution of $\text{s = (1.7}\text{A}\text{?}\text{)}{}^{\mathrm{?1}}$ have been recorded.     

Letter: Crystallization and preliminary x-ray diffraction studies on tyrosyl-transfer RNA synthetase from Bacillus stearothermophilus

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 $\text{a = 64.4}\text{A}\text{?}$ and $\text{c = 238}\text{A}\text{?}$; 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.     

Crystallographic study on the orthorhombic crystal of l-asparaginase from Escherichia coli HAP

The orthorhombic crystals of l-asparaginase from Escherichia coli A-1-3 KY3598 were characterized by the X-ray diffraction method as belonging to the space group P2₁22₁ with unit cell dimensions $\text{a = 116.7}\text{A}\text{?}\text{, b = 62.9}\text{A}\text{?}\text{and}\text{c = 86.6}\text{A}\text{?}$. The crystals contain one half of the tetrameric enzyme molecule per asymmetric unit, the smallest so far reported for this enzyme. Preliminary analysis of the Patterson map indicated that the molecule had at least pseudo 222 symmetry and established the position of the centers of the molecules in the unit cell.     

Preliminary crystallographic study of omega-amino acid: pyruvate aminotransferase from Pseudomonas sp. F-126.

Large single crystals of ω-amino acid: pyruvate aminotransferase, were prepared by dialysis of the enzyme solution against 2.2 m-ammonium sulphate solution at pH 7.8. X-ray diffraction patterns show that the crystals belong to the orthorhombic space group I222 or I2₁2₁2₁ with unit cell dimensions $\text{a = 124.1}\text{A}\text{?}\text{, b = 137.9}\text{A}\text{?}\text{, and}\text{c = 61.2}\text{A}\text{?}$. The asymmetric unit consists of one monomer of molecular weight 43,000.     

The structure of form I crystals of D-ribulose-1,5-diphosphate carboxylase.

Single crystals of d-ribulose-1,5-diphosphate carboxylase from tobacco leaves, Nicotiana tabacum (variety Turkish Samsun), have been examined by X-ray diffraction, electron microscopy, and optical diffraction. Twelve molecules are loosely packed into a body-centered cubic unit cell, space group I4¹32 with cell dimension $\text{a = 383}\text{A}\text{̊}$. The asymmetric unit is one quarter of a molecule, and the minimum molecular symmetry is 222. This symmetry when combined with estimates of the two subunit masses and stoichiometry is compatible with a molecular structure of the composition L₈S₈ (L is large subunit, S is small). If all bonds between large and small subunits are equivalent, the true molecular symmetry is 422; this symmetry is consistent with molecular images in micrographs.     

Crystallization of a DNA-unwinding protein: Preliminary X-ray analysis of fd bacteriophage gene 5 product

The gene 5 protein from bacteriophage fd, which binds to single-stranded progeny fd DNA, was obtained as large single crystals and subjected to X-ray diffraction analysis. The crystals are of monoclinic space group C2 with $\text{a = 75.8}\text{A}\text{?}\text{, b = 28.0}\text{A}\text{?}\text{, c = 42.5}\text{A}\text{?}\text{and}\text{β = 103 °12′}$. The unit cell has one molecule of 9800 daltons as the asymmetric unit.     

Crystallization of belladonna mottle virus

Belladonna mottle virus belongs to the turnip yellows mosaic virus group of the small spherical plant viruses. It contains 180 protein subunits, which are arranged in a T = 3 icosahedral surface lattice. The top and bottom viral components crystallize isomorphously in hexagonal space group R3 ($\text{a = b = 296}\text{A}\text{?}\text{, c = 729}\text{A}\text{?}$). The unit cell contains three virus particles, while the crystallographic asymmetric unit consists of only one-third of a particle. X-ray diffraction data from the crystals extend to at least 3.8 Å resolution.     

Highly ordered crystals of the plant seed protein crambin.

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 $\text{a = 41.1}\text{A}\text{?}\text{, b = 18.7}\text{A}\text{?}\text{, c = 22·7}\text{A}\text{?}\text{,}\text{and}\text{β = 90.6 °}$. The asymmetric unit contains one protein molecule.     

Crystallization of exotoxin A from Pseudomonas aeruginosa

Exotoxin A from Pseudomonas aeruginosa has been crystallized in a form suitable for high resolution diffraction analysis. The crystals, grown in the presence of high concentrations of polyethylene glycol (20%, w/v) and of NaCl (1.5 m), are monoclinic and contain one monomeric toxin molecule per asymmetric unit. The space group is P2₁, with $\text{a = 60.6}\text{A}\text{?}\text{, b = 100.2}\text{A}\text{?}\text{, c = 59.8}\text{A}\text{?}\text{, β = 98.6 °}$.     

A tetragonal crystal form of horse spleen apoferritin and its relationship to the cubic modification

Horse spleen apoferritin has been crystallized as tetragonal plates and needles with a unit cell with $\text{a = b = 147 ± 0.5}\text{A}\text{?}\text{and}\text{c = 154.4 ± 0.5}\text{A}\text{?}$. The space group is P42₁2 and the unit cell contains two molecules in a pseudo-body-centred arrangement. The intensity distributions and calculated rotation functions of tetragonal and cubic crystals have been compared. The symmetry of the diffraction patterns from cubic crystals indicates that the molecules have 432 symmetry with their 4-fold axes lying along the cube axes. In the tetragonal crystals one molecular 4-fold axis lies parallel to c, the unique axis, while the rest of the molecular point symmetry is not used by the lattice. Instead the remaining 4-fold axes of the two molecules, which lie in planes perpendicular to c, are rotated ± 17.5 ° with respect to the tetragonal a axis. The finding that apoferritin reassembled from subunits can be crystallized in both tetragonal and cubic forms confirms its conformational similarity to native molecules.     

Crystals of glutamine synthetase from Escherichia coli.

Further details are given of crystals of glutamine synthetase prepared from Escherichia coli. Crystals of two kinds have been observed: (1) rhombic dodecahedra which correspond to the morphology of the crystals studied by Eisenberg et al. (1971) (and which were found by them to contain dodecamers), and (2) rhombohedra, reported here. Cell dimensions and packing considerations led to the consideration of two possible structures for the rhombohedral crystals. These we have called the “T = 7 structure” and the “B.C.C. structure”. The T = 7 structure would be related to that derived by Eisenberg and would contain dodecamers, but is inconsistent with our X-ray intensity data. The B.C.C. structure is considered more probable. It is built of cubic octomers or square tetramers. Electron micrographs of our glutamine synthetase preparations show a wide variety of aggregates, including dodecamers and tetramers. The unit cell dimensions of our crystals are $\text{a = 140 ± 2}\text{A}\text{̊}$, and $\text{c = 148 ± 2}\text{A}\text{̊}$. The Laue symmetry group is $\text{3}\text{̄}$m P3₁.     

Particle and crystal symmetry of erysimum latent virus

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 $\text{a = 414}\text{A}\text{?}$) and a monoclinic form (space group B2, $\text{a = 442}\text{A}\text{?}\text{, b = 422}\text{A}\text{?}\text{, c = 387}\text{A}\text{?}\text{, γ = 95 °}$) 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.     

Letter: Crystallization and preliminary x-ray investigation of bovine erythrocyte carbonic anhydrase

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 $\text{a = b = 68}\text{A}\text{?}$, $\text{c = 244}\text{A}\text{?}$.     

Purification and preliminary crystallographic studies on azurin and cytochrome c' from Alcaligenes denitrificans and Alcaligenes sp. NCIB 11015.

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 $\text{a = 75.0}\text{A}\text{?}\text{, b = 74.1}\text{A}\text{?}\text{, c = 99.5}\text{A}\text{?}$, with two molecules per asymmetric unit. The cytochrome c′ crystals from both species are hexagonal, space group P6₁22 (or P6₅22), cell dimensions $\text{a = b = 54.7}\text{A}\text{?}\text{, c ~ 185}\text{A}\text{?}$, γ = 120 °, with one subunit (molecular weight 14,000) in the asymmetric unit.     

Electron diffraction study on single crystals of l-type and dl-type lecithins

An electron diffraction study was carried out on thin single micro-crystals of l-type and dl-type dipalmitoyl lecithins grown in xylene suspensions and fine net patterns were obtained and the mechanism of the thermotropic phase transitions of them was clarified.From the apparent structure of diffraction patterns in low temperature, it is confirmed that the two dimensional lattices have p mm symmetry in l-type and in dl-type lecithins. Lattice parameters from the [001] projection are $\text{d}{}_{100}\text{= 9.9}\text{A}\text{?}$ and $\text{d}{}_{010}\text{= 8.8}\text{A}\text{?}$ in l-type, and $\text{d}{}_{100}\text{= 17.2}\text{A}\text{?}$ and $\text{d}{}_{010}\text{= 8.9}\text{A}\text{?}$ in dl-type.With anisotropic variation of dimensions along a and b axes, i.e. contraction for a and expansion for b, induced by temperature rise by electron irradiation during the observation, these diffraction patterns of the lattices of l-type and dl-type were transformed into those characterized by the six diffraction spots having nearly the same spacings. Four of them are observed on slightly outer and two are slightly inner positions as compared with their mean spacings of about (4.1 Å)^?1 in l-type and about (4.2 Å)^?1 in dl-type. The changes in the patterns observed indicate that at low temperatures the hydrocarbon chains are nearly perpendicular to the layer in dl-type lipid, and tilted with a more complicated packing in l-type ones. The dimension along a in dl-type is twice as large as that in l-type.     

A preliminary crystallographic study of wheat germ agglutinin

Wheat germ agglutinin crystallizes in two monoclinic space groups, P2₁ and C2, under identical crystallization conditions. Unit cell dimensions are $\text{a = 73.8}\text{A}\text{?}\text{, b = 51.2}\text{A}\text{?}\text{, c = 90.8}\text{A}\text{?}\text{, γ = 90 °}$ for $\text{P2}{}_1\text{; a = 51.31}\text{A}\text{?}\text{, b = 73.35}\text{A}\text{?}\text{, c = 91.45}\text{A}\text{?}\text{, β = 97.75 °}$ 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.     

Characterization and preliminary crystallographic data on the VL-related fragment of the human kI Bence Jones protein Wat

A “naturally occurring” human κI V_L 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 (V_L) 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 V_L dimer Wat were obtained from ammonium sulfate or polyethylene glycol solutions. The type I crystals have unit cell dimensions of $\text{a = b = 82.6}\text{A}\text{?}\text{, c = 60.3}\text{A}\text{?}$, and the space group is hexagonal P6₂ or P6₄. The asymmetric unit consists of one V_L dimer; the fractional volume of unit cell occupied by solvent is 0.51. The unit cell dimensions of the type II crystals are $\text{a = b = 1,08.3}\text{A}\text{?}\text{, c = 108.8}\text{A}\text{?}$; 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.     

Isolation,crystallization and preliminary crystallographic data of aspartate aminotransferase from chicken heart mitochondria

The mitochondrial isoenzyme of aspartate aminotransferase (E.C. 2.6.1.1) has been isolated from chicken heart in an electrophoretically and immunologically homogeneous form. Large, well-diffracting single crystals of this enzyme, a dimeric molecule with a molecular weight of 90,000, have been grown by vapour phase diffusion against polyethylene glycol solutions. The crystals belong to space group P1. The unit cell, with the dimensions $\text{a = 55.6}\text{A}\text{?}\text{, 6 = 58.7}\text{A}\text{?}\text{, c = 76.0}\text{A}\text{?}$, α = 85.3 °, β = 109.2 °, γ = 115.6 °, contains a single dimer. The diffraction pattern extends to at least 2.1 Å resolution.     

Preliminary x-ray diffraction studies on the "goose-type" lysozyme from the egg-white of the black swan Cygnus atratus

The “goose-type” lysozyme isolated from the egg-white of the black swan Cygnus atratus has been crystallized. The space group is P2₁ with one molecule of protein in the asymmetric unit. The cell parameters are $\text{a = 46.2}\text{A}\text{?}\text{, b = 65.1}\text{A}\text{?}\text{, c = 38.7}\text{A}\text{?}$, β = 110 °. The crystals diffract to a resolution of 2.25 Å and a set of diffraction data for the native protein has been collected photographically.     

Crystallographic analysis of the phytoagglutinin from Abrus precatorius by X-ray diffraction and electron microscopy

The lectin from the seeds of Abrus precatorius has been crystallized and the crystals subjected to study by X-ray diffraction and electron microscopy. Three closely related crystal forms were obtained, of orthorhombic space group P2₁2₁2₁ with $\text{a = 138}\text{A}\text{?}$, $\text{b = 142}\text{A}\text{?}$, and $\text{c = 173}\text{A}\text{?}$, of tetragonal space group P4₁2₁2 with $\text{a = b = 136}\text{A}\text{?}$, $\text{c = 176}\text{A}\text{?}$, and a twinned intermediate of the first two. From electron microscopy and two-dimensional spatial filtering of electron micrographs of the crystals, the molecule appears to consist of four similar domains grouped in a roughly planar diamond-shaped arrangement having a local intramolecular dyad axis. The average diameter of the Abrus lectin molecule is 50 to 60 Å and the individual domains appear to have a diameter of about 25 Å.