Purification, crystallization and preliminary X-ray analysis of catabolic ornithine carbamoyltransferase from Pseudomonas aeruginosa

1999 ◽  
Vol 55 (9) ◽  
pp. 1591-1593 ◽  
Author(s):  
G. Sainz ◽  
J. Vicat ◽  
R. Kahn ◽  
C. Tricot ◽  
V. Stalon ◽  
...  

The catabolic ornithine carbamoyltransferase (OTCase) from Pseudomonas aeruginosa exhibits allosteric behaviour, with two conformational states of the molecule: an active R form and an inactive T form. The enzyme is a dodecamer with a molecular mass of 455700 Da. Three crystal forms have been obtained. Crystals of allosteric state T are rhombohedral, belonging to the R3 space group, with hexagonal unit-cell parameters a = b = 180.6, c = 122.0 Å. They diffract to a resolution of 4.5 Å. Two crystal forms for allosteric state R have been obtained, with hexagonal and cubic symmetries. Hexagonal crystals, which diffract to a resolution of 3.4 Å, belong to the space group P63 with unit-cell parameters a = b = 140.8, c = 145.6 Å. The cubic crystals belong to space group I23, with unit-cell parameter a = 134.32 Å and diffract to a resolution better than 2.5 Å. In all crystal forms, the dodecamer exhibits a 23 point-group symmetry.

1999 ◽  
Vol 55 (4) ◽  
pp. 907-909 ◽  
Author(s):  
Jun Masuda ◽  
Tetsuya Yamaguchi ◽  
Takamasa Tobimatsu ◽  
Tetsuo Toraya ◽  
Kyoko Suto ◽  
...  

Two crystal forms of Klebsiella oxytoca diol dehydratase complexed with cyanocobalamin have been obtained and preliminary crystallographic experiments have been performed. The crystals belong to two different space groups, depending on the crystallization conditions. One crystal (form I) belongs to space group P212121 with unit-cell parameters a = 76.2, b = 122.3, c = 209.6 Å, and diffracts to 2.2 Å resolution using an X-ray beam from a synchrotron radiation source. The other crystal (form II) belongs to space group P21 with unit-cell parameters a = 75.4, b = 132.7, c = 298.8 Å, β = 91.9°, and diffracts to 3.0 Å resolution. For the purpose of structure determination, a heavy-atom derivative search was carried out and some mercuric derivatives were found to be promising. Structure analysis by the multiple isomorphous replacement method is now under way.


2015 ◽  
Vol 79 (2) ◽  
pp. 321-335 ◽  
Author(s):  
Stuart J. Mills ◽  
Andrew G. Christy ◽  
Fernando Colombo ◽  
Jason R. Price

AbstractWe report the single-crystal average structure of cyanotrichite, Cu4Al2[SO4](OH)12(H2O)2, from the Maid of Sunshine mine, Arizona, USA. Cyanotrichite crystallizes in space group C2/m, with the unit-cell parameters a = 12.625(3), b = 2.8950(6), c = 10.153(2) Å and β = 92.17(3)o. All non-hydrogen atoms were located and refined to R1 = 0.0394 for all 584 observed reflections [Fo > 4σFo] and 0.0424 for all 622 unique reflections. The cyanotrichite structure consists of a principal building unit of a three-wide [Cu2Al(OH)6] ribbon of edge-sharing Cu and Al polyhedra || b, similar to that found for camerolaite. The ribbons lie in layers || (001) and between these layers, while SO4 tetrahedra and H2O molecules form rods running || b. A hydrogen-bonding scheme is also proposed.A sample of cyanotrichite from the Cap Garonne mine, Le Pradet, France, showed a 4b superstructure with the following unit cell: space group P2/m, a = 12.611(2) Å, b = 11.584(16) = 4 × 2.896(4) Å, c = 10.190(1) Å and β = 92.29(6)o. The supercell could not be refined in detail, but nevertheless imposes constraints on the local structure in that while the space-group symmetry prevents full order of SO4 and H2O in the 4b supercell, it requires that the sequence of species along any given rod is [-SO4-SO4-(H2O)2-(H2O)2-] rather than [-SO4-(H2O)2-SO4-(H2O)2-].


Author(s):  
San Hadži ◽  
Abel Garcia-Pino ◽  
Kenn Gerdes ◽  
Jurij Lah ◽  
Remy Loris

The HigA2 antitoxin and the HigBA2 toxin–antitoxin complex fromVibrio choleraewere crystallized in complex with their operator box. Screening of 22 different DNA duplexes led to two crystal forms of HigA2 complexes and one crystal form of a HigBA2 complex. Crystals of HigA2 in complex with a 17 bp DNA duplex belong to space groupP3221, with unit-cell parametersa=b= 94.0,c= 123.7 Å, and diffract to 2.3 Å resolution. The second form corresponding to HigA2 in complex with a 19 bp duplex belong to space groupP43212 and only diffract to 3.45 Å resolution. Crystals of the HigBA2 toxin–antitoxin were obtained in complex with a 31 bp duplex and belonged to space groupP41212, with unit-cell parametersa=b= 113.6,c= 121.1 Å. They diffract to 3.3 Å resolution.


Author(s):  
Dan Sato ◽  
Tomoo Shiba ◽  
Sae Mizuno ◽  
Ayaka Kawamura ◽  
Shoko Hanada ◽  
...  

Cystathionine γ-synthase (CGS; EC 2.5.1.48), a pyridoxal 5′-phosphate (PLP)-dependent enzyme, catalyzes the formation of cystathionine from an L-homoserine derivative and L-cysteine in the first step of the transsulfuration pathway. Recombinant CGS from the thermoacidophilic archaeonSulfolobus tokodaii(StCGS) was overexpressed inEscherichia coliand purified to homogeneity by heat treatment followed by hydroxyapatite and gel-filtration column chromatography. The purified enzyme shows higher enzymatic activity at 353 K under basic pH conditions compared with that at 293 K. Crystallization trials yielded three crystal forms from different temperature and pH conditions. Form I crystals (space groupP21; unit-cell parametersa= 58.4,b= 149.3,c= 90.2 Å, β = 108.9°) were obtained at 293 K under acidic pH conditions using 2-methyl-2,4-pentanediol as a precipitant, whereas under basic pH conditions the enzyme crystallized in form II at 293 K (space groupC2221; unit-cell parametersa= 117.7,b= 117.8,c= 251.3 Å) and in form II′ at 313 K (space groupC2221; unit-cell parametersa= 107.5,b= 127.7,c= 251.1 Å) using polyethylene glycol 3350 as a precipitant. X-ray diffraction data were collected to 2.2, 2.9 and 2.7 Å resolution for forms I, II and II′, respectively. Structural analysis of these crystal forms shows that the orientation of the bound PLP in form II is significantly different from that in form II′, suggesting that the change in orientation of PLP with temperature plays a role in the thermophilic enzymatic activity of StCGS.


Author(s):  
Annette M. Bodenheimer ◽  
Matthew J. Cuneo ◽  
Paul D. Swartz ◽  
Junhong He ◽  
Hugh M. O'Neill ◽  
...  

Cel7A (previously known as cellobiohydrolase I) fromHypocrea jecorinawas crystallized in two crystalline forms, neither of which have been previously reported. Both forms co-crystallize under the same crystallization conditions. The first crystal form belonged to space groupC2, with unit-cell parametersa= 152.5,b= 44.9,c= 57.6 Å, β = 101.2°, and diffracted X-rays to 1.5 Å resolution. The second crystal form belonged to space groupP6322, with unit-cell parametersa=b≃ 155,c≃ 138 Å, and diffracted X-rays to 2.5 Å resolution. The crystals were obtained using full-length Cel7A, which consists of a large 434-residue N-terminal catalytic domain capable of cleaving cellulose, a 27-residue flexible linker and a small 36-residue C-terminal carbohydrate-binding module (CBM). However, a preliminary analysis of the electron-density maps suggests that the linker and CBM are disordered in both crystal forms. Complete refinement and structure analysis are currently in progress.


Author(s):  
Hee-Jung Choi ◽  
William I. Weis

β-Catenin is a multifunctional protein involved in both cell adhesion and Wnt signaling in metazoans. The nematodeCaenorhabditis elegansis unusual in that it expresses four β-catenin paralogs with separate functions.C. elegansHMP-2 participates in cell adhesion but not in Wnt signaling, so structural and biochemical studies of this protein will help in understanding its unusual specialization and the evolution of β-catenin. HMP-2 was expressed, purified and crystallized in two different salt conditions. Crystals grown from a sodium formate condition diffracted to a resolution of 2 Å and belonged to space groupC2, with unit-cell parametersa= 165.2,b= 39.0,c= 101.1 Å, β = 116.7°. Crystals obtained from a lithium sulfate condition diffracted to 3 Å resolution and belonged to space groupP43, with unit-cell parametersa=b= 85.3,c= 138.7 Å. Diffraction data were collected and processed from both crystal forms and the structure was solved by molecular replacement. Model refinement is in progress.


1999 ◽  
Vol 55 (4) ◽  
pp. 895-897 ◽  
Author(s):  
Laurent Chantalat ◽  
Didier Leroy ◽  
Odile Filhol ◽  
Nora Quitaine ◽  
Edmond M. Chambaz ◽  
...  

Protein kinase CK2 is a tetramer composed of two α catalytic subunits and two β regulatory subunits. A C-terminal truncated form of the β subunit has been overproduced in Escherichia coli and purified to homogeneity. Two crystal forms of the truncated protein which diffract to at least 2 Å resolution have been obtained. Form I belongs to the monoclinic space group P21, with unit-cell parameters a = 49.9, b = 92.9, c = 53.7 Å, β = 96.3°, and yields plate-like crystals. Form II belongs to the tetragonal space group P42212, with unit-cell parameters a = 132.19, b = 132.19, c = 63.79 Å, and produces rod-shaped crystals. Both crystal forms have a functional dimer in the crystal asymmetric unit.


2014 ◽  
Vol 70 (11) ◽  
pp. 1468-1471
Author(s):  
Trung Thanh Thach ◽  
Sangho Lee

Adenylate kinases (AdKs; EC 2.7.3.4) play a critical role in intercellular homeostasis by the interconversion of ATP and AMP to two ADP molecules. Crystal structures of adenylate kinase fromStreptococcus pneumoniaeD39 (SpAdK) have recently been determined using ligand-free and inhibitor-bound crystals belonging to space groupsP21andP1, respectively. Here, new crystal structures of SpAdK in ligand-free and inhibitor-bound states determined at 1.96 and 1.65 Å resolution, respectively, are reported. The new ligand-free crystal belonged to space groupC2, with unit-cell parametersa= 73.5,b= 54.3,c= 62.7 Å, β = 118.8°. The new ligand-free structure revealed an open conformation that differed from the previously determined conformation, with an r.m.s.d on Cαatoms of 1.4 Å. The new crystal of the complex with the two-substrate-mimicking inhibitorP1,P5-bis(adenosine-5′-)pentaphosphate (Ap5A) belonged to space groupP1, with unit-cell parametersa= 53.9,b= 62.3,c= 63.0 Å, α = 101.9, β = 112.6, γ = 89.9°. Despite belonging to the same space group as the previously reported crystal, the new Ap5A-bound crystal contains four molecules in the asymmetric unit, compared with two in the previous crystal, and shows slightly different lattice contacts. These results demonstrate that SpAdK can crystallize promiscuously in different forms and that the open structure is flexible in conformation.


1998 ◽  
Vol 54 (3) ◽  
pp. 211-220 ◽  
Author(s):  
R. P. Hammond ◽  
J. Barbier

Hexagonal (Na3/4K1/4)AlGeO4 crystallizes in the space group P63 with unit-cell parameters a = 10.164 (2), c = 8.540 (2) Å and Z = 8 [wR(F 2) = 0.066 for all 3060 independent reflections]. Monoclinic (Na3/4K1/4)AlGeO4 crystallizes in the space group P21 with unit-cell parameters a = 10.0477 (4), b = 8.5764 (4), c = 10.2118 (4) Å, β = 119.035 (1)° and Z = 8 [wR(F 2) = 0.120 for all 3194 independent reflections measured on a twinned crystal]. Both structures belong to the large family of stuffed tridymites, with the Al and Ge atoms occupying tetrahedral sites, and the alkali atoms occupying the cavities of the tetrahedral framework. Hexagonal (Na3/4K1/4)AlGeO4 is isostructural with the silicate mineral nepheline (Na3/4K1/4)AlSiO4, while monoclinic (Na3/4K1/4)AlGeO4 corresponds to a minor distortion of the nepheline structure. Chemical analysis by electron microprobe and structure determination of flux-grown single crystals indicate that the hexagonal form with the chemical formula (Na0.78K0.19)Al0.97Ge1.03O4 may be stabilized by an alkali deficiency similar to that found in hexagonal natural nephelines. In contrast, all alkali sites are fully occupied in the monoclinic form of composition (Na0.75K0.25)AlGeO4 and the lower symmetry eliminates the oxygen disorder present in the hexagonal form.


2021 ◽  
pp. 1-3
Author(s):  
J. Maixner ◽  
J. Ryšavý

X-ray powder diffraction data, unit-cell parameters, and space group for tetrazene nitrate monohydrate, C2H9N11O4, are reported [a = 5.205(1) Å, b = 13.932(3) Å, c = 14.196(4) Å, β = 97.826(3)°, unit-cell volume V = 1019.8(4) Å3, Z = 4, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.


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