Crystallization and preliminary X-ray analysis of the formiminotransferase domain from the bifunctional enzyme formiminotransferase–cyclodeaminase

1999 ◽  
Vol 55 (6) ◽  
pp. 1206-1208 ◽  
Author(s):  
Darcy Kohls ◽  
Nathalie Croteau ◽  
Narciso Mejia ◽  
Robert E. MacKenzie ◽  
Alice Vrielink

Formiminotransferase–cyclodeaminase (E.C. 2.1.2.5–E.C. 4.3.1.4) is a bifunctional enzyme involved in the histidine-degradation pathway which exhibits specificity for polyglutamylated folate substrates. The first function of the enzyme transfers the formimino group of formiminoglutamate to the N 5 position of tetrahydrofolate, while the second function catalyses the cyclodeamination of the formimino group, yielding N 5,10-methenyl-tetrahydrofolate, with efficient channeling of the intermediate between these activities. Initial studies have shown that the enzyme consists of eight identical subunits of 62 kDa each, arranged as a circular tetramer of dimers. It is this formation which results in two different dimeric interfaces, which are necessary for the two different activities. The identical subunits have been shown to consist of two domains, each of which can be obtained as dimers. The formiminotransferase domain has been crystallized in the presence of the substrate analogue folinic acid. The crystals belong to space group P212121, with unit-cell dimensions a = 64.4, b = 103.7, c = 122.3 Å. Both a native data set and a mercurial derivative data set have been collected to 2.8 Å resolution.

1999 ◽  
Vol 55 (4) ◽  
pp. 869-872 ◽  
Author(s):  
Anna Teplitsky ◽  
Smadar Shulami ◽  
Sara Moryles ◽  
Galia Zaide ◽  
Yuval Shoham ◽  
...  

α-D-Glucuronidases cleave the α-1,2-glycosidic bond of the 4-O-methyl-α-D-glucuronic acid side chain in xylan. Of the xylan-debranching hydrolases, these enzymes are the least studied and characterized. The α-glucuronidase gene (aguA) from Bacillus stearothermophilus T-6 has been cloned, sequenced and overproduced in Escherichia coli. The gene encodes for a protein of 679 amino acids with a calculated molecular weight of 78480 and a pI of 5.42. α-Glucuronidase T-6 shows high homology to the α-glucuronidases of Thermotoga maritima (60% identity) and of Trichoderma reesei (44% identity). Based on the amino-acid sequence similarity, it is likely that these enzymes represent a new class of glycosyl hydrolases. Crystallographic studies of α-glucuronidase T-6 were initiated to study the mechanism of catalysis, as well as to provide a structural basis for rational introduction of enhanced thermostability by site-specific mutagenesis. In this report, the crystallization and preliminary crystallographic characterization of the native α-glucuronidase T-6 enzyme is described. Two crystal forms were found suitable for detailed crystal structure analysis. The T1 form was obtained by the vapour-diffusion method using PEG 4000 as a precipitant and 2-propanol as an organic additive. The crystals belong to a primitive tetragonal crystal system (space group P41212 or P43212) with unit-cell dimensions a = b = 76.1 and c = 331.2 Å. These crystals are mechanically strong, are stable in the X-ray beam and diffract X-rays to better than 2.4 Å resolution. A full 3.0 Å resolution diffraction data set (97.3% completeness, R merge 9.8%) has recently been collected on one crystal at room temperature using a rotating-anode X-ray source and an R-AXIS IIc imaging-plate detector. The M1 form was obtained and characterized by similar techniques. The best crystallization occurred at a slightly lower pH and a lower concentration of 2-propanol. The crystals belong to a primitive monoclinic crystal system (space group P21) with unit-cell dimensions a = 65.8, b = 127.4, c = 96.6 Å and β = 97.9°. These crystals are also quite strong and stable, and diffract to better than 2.8 Å resolution. A full 2.8 Å resolution diffraction data set (96.2% completeness, R merge 7.6%) has recently been collected on one crystal at room temperature using the same R-AXIS IIc setup. Both forms are currently being used to obtain crystallographic phasing via isomorphous heavy-atom derivatives and selenomethionine MAD experiments.


1998 ◽  
Vol 54 (3) ◽  
pp. 436-436 ◽  
Author(s):  
Hee-Jeong Choi ◽  
Sang Won Kang ◽  
Chul-Hak Yang ◽  
Sue Goo Rhee ◽  
Seong-Eon Ryu

HORF6 is a member of the novel antioxidant enzyme family found in humans. A recombinant form of hORF6 expressed and purified from E. coli has been crystallized by the hanging-drop method using various PEG's as precipitating agents. HORF6 crystallizes in two different monoclinic space groups, P21 and C2. The P21 crystals have unit-cell dimensions of a = 47.85, b = 75.17, c = 63.30 Å and β = 110.21° and contain two monomers per asymmetric unit, while the C2 crystals have unit-cell dimensions of a = 165.27, b = 95.44, c = 166.44 Å and β = 128.97° and contain more than six monomers per asymmetric unit. The P21 crystals with the smaller unit cell diffract X-rays better and behave well for the X-ray analysis. A native data set from a single crystal of the P21 space group gas been collected to 2.0 Å resolution.


1998 ◽  
Vol 54 (3) ◽  
pp. 446-447 ◽  
Author(s):  
Min-Qin Chen ◽  
Chang-Chuan Yin ◽  
Wei Zhang ◽  
Yu-Min Mao ◽  
Zhi-Hong Zhang

The thermostable catechol 2,3-dioxygenase of Bacillus stearothermophilus has been crystallized. The crystal is probably in the space group I 222 with unit-cell dimensions of a = 70.87, b = 74.60 and c = 133.69 Å. A native data set has been collected with a completeness of 96% at 2.22 Å resolution and an R merge value of 0.091.


Author(s):  
L. W. Labaw

Crystals of a human γGl immunoglobulin have the external morphology of diamond shaped prisms. X-ray studies have shown them to be monoclinic, space group C2, with 2 molecules per unit cell. The unit cell dimensions are a = 194.1, b = 91.7, c = 51.6Å, 8 = 102°. The relatively large molecular weight of 151,000 and these unit cell dimensions made this a promising crystal to study in the EM.Crystals similar to those used in the x-ray studies were fixed at 5°C for three weeks in a solution of mother liquor containing 5 x 10-5M sodium phosphate, pH 7.0, and 0.03% glutaraldehyde. They were postfixed with 1% osmium tetroxide for 15 min. and embedded in Maraglas the usual way. Sections were cut perpendicular to the three crystallographic axes. Such a section cut with its plane perpendicular to the z direction is shown in Fig. 1.This projection of the crystal in the z direction shows periodicities in at least four different directions but these are only seen clearly by sighting obliquely along the micrograph.


1996 ◽  
Vol 11 (4) ◽  
pp. 301-304
Author(s):  
Héctor Novoa de Armas ◽  
Rolando González Hernández ◽  
José Antonio Henao Martínez ◽  
Ramón Poméz Hernández

p-nitrophenol, C6H5NO3, and disophenol, C6H3I2NO3, have been investigated by means of X-ray powder diffraction. The unit cell dimensions were determined from diffractometer methods, using monochromatic CuKα1 radiation, and evaluated by indexing programs. The monoclinic cell found for p-nitrophenol was a=6.159(2) Å, b=8.890(2) Å, c=11.770(2) Å, β=103.04(2)°, Z=4, space group P21 or P2l/m, Dx=1.469 Mg/m3. The monoclinic cell found for disophenol has the dimensions a=8.886(1) Å, b=14.088(2) Å, c=8.521(1) Å, β=91.11(1)°, Z=4, space group P2, P2, Pm or P2/m, Dx=2.438 Mg/m3.


1999 ◽  
Vol 55 (2) ◽  
pp. 539-541
Author(s):  
Palangpon Kongsaeree ◽  
Jun Liang ◽  
Roy A. Jensen ◽  
Jon Clardy

The title protein has been crystallized in a new crystal form. The crystals belong to the cubic space group P4132 (or P4332) with unit-cell dimensions a = b = c = 126.1 Å at 100 K and typically diffract beyond 1.6 Å at the Cornell High Energy Synchotron Source (CHESS) A1 beamline.


1976 ◽  
Vol 31 (9) ◽  
pp. 1175-1178 ◽  
Author(s):  
Kurt Walenta

A new compound having the same composition as zircon, ZrSiO4, but differing from it in its structure has been obtained by heating zircon particles to a temperature of 5000 to 10000°K. According to X-ray powder diffraction data the structure and within limits of error also the unit-cell dimensions are identical with that of monoclinic baddeleyite, ZrO2. This suggests that the baddeleyite lattice can not only accommodate 10 molecular % SiO2 as is already known for some time, but substantially more, unless it is assumed that some kind of submicroscopic exsolution of amorphous SiO2 has taken place.


Detailed interpretations of the X -ray diffraction patterns of fibres and sheets of 66 and 6.10 polyamides (polyhexam ethylene adipamide and sebacamide respectively) are proposed. The crystal structures of the two substances are completely analogous. Fibres of these two polyam ides usually contain two different crystalline forms, α and β, which are different packings of geometrically similar molecules; most fibres consist chiefly of the α form. In the case of the 66 polymer, fibres have been obtained in which there is no detectable proportion of the β form. Unit cell dimensions and the indices of reflexions for the α form were determined by trial, using normal fibre photographs, and were checked by using doubly oriented sheets set at different angles to the X -ray beam. The unit cell of the a form is triclinic, with a — 4·9 A, b = 5·4 A, c (fibre axis) = 17·2A, α = 48 1/2º, β = 77º, γ = 63 1/2º for the 66 polymer; a = 4·95A, b = 5·4A, c (fibre axes) = 22·4A, α = 49º, β = 76 1/2º, γ = 63 1/2º for the 6.10 polymer. One chain molecule passes through the cell in both cases. Atomic coordinates in occrystals were determined by interpretation of the relative intensities of the reflexions. The chains are planar or very nearly so; the oxygen atoms appear to lie a little off the plane of the chain. The molecules are linked by hydrogen bonds between C = 0 and NH groups, to form sheets. A simple packing of these sheets of molecules gives the α arrangement.


2007 ◽  
Vol 62 (6) ◽  
pp. 868-870 ◽  
Author(s):  
Johanna Kutuniva ◽  
Raija Oilunkaniemi ◽  
Risto S. Laitinen ◽  
Janne Asikkala ◽  
Johanna Kärkkäinen ◽  
...  

1-Butyl-2,3-dimethylimidazolium bromide {(bdmim)Br} (1) and iodide {(bdmim)I} (2) were prepared conveniently by the reaction of 1,2-dimethylimidazole and the corresponding 1-halobutane. The compounds were characterized by 1H and 13C{1H} NMR spectroscopy as well as by X-ray single crystal crystallography. 1 crystallizes in the monoclinic crystal system, space group P21/n, with Z = 4, and unit cell dimensions a = 8.588(2), b = 11.789(1), c = 10.737(2) Å, β = 91.62(3)°. Compound 2 crystallizes in the monoclinic crystal system, space group P21/c, with Z = 8, and unit cell dimensions a = 10.821(2), b = 14.221(3), c = 15.079(2) Å , β = 90.01(3)°. The lattices of the salts are built up of 1-butyl-2,3- dimethylimidazolium cations and halide anions. The cations of 1 form a double layer with the imidazolium rings stacked together due to π interactions. The Br− anions lie approximately in the plane of the imidazolium ring, and the closest interionic Br···H contacts span a range of 2.733(1) - 2.903(1) Å. Compound 2 shows no π stacking interactions. The closest interionic I···H contacts are 2.914(1) - 3.196(1) Å


1999 ◽  
Vol 55 (12) ◽  
pp. 2033-2034 ◽  
Author(s):  
Youwei Yan ◽  
Sanjeev Munshi ◽  
Ying Li ◽  
Kelly Ann D. Pryor ◽  
Frank Marsilio ◽  
...  

Crystals of the Escherichia coli UDP-MurNAc-tripeptide D-Ala-D-Ala-adding protein (MurF), which catalyzes the formation of the last metabolite of the bacterial cell-wall building block, have been grown in hanging-drop vapor-diffusion trials using PEG 8K as a precipitating agent. The crystals belong to hexagonal space group P61 or P65, with unit-cell dimensions a = b = 74, c = 425 Å. The asymmetric unit contains two molecules, with a crystal volume per protein mass (Vm ) of 3.4 Å3 Da−1 and a solvent content of about 64% by volume. A native data set to 2.8 Å resolution has been obtained from a frozen crystal using a synchrotron X-ray source.


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