Effects of microgravity on the crystal quality of a collagen-like polypeptide

2000 ◽  
Vol 56 (1) ◽  
pp. 55-61 ◽  
Author(s):  
R. Berisio ◽  
L. Vitagliano ◽  
G. Sorrentino ◽  
L. Carotenuto ◽  
C. Piccolo ◽  
...  

(Pro-Pro-Gly)10 is one of the most widely studied collagen polypeptide models. Microgravity crystal growth of (Pro-Pro-Gly)10 was carried out in the Advanced Protein Crystallization Facility aboard the Space Shuttle Discovery during the STS-95 mission. Crystals were successfully grown in all experiments, using both dialysis and free-interface diffusion methods. The quality of the microgravity-grown crystals and of ground-grown counterparts was assessed by X-ray synchrotron diffraction. Microgravity-grown crystals exhibited a significant improvement in terms of dimensions and resolution limit. As previously reported, crystals were orthorhombic, space group P212121. However, the diffraction pattern showed weak reflections, never previously measured, that were consistent with new unit-cell parameters a = 26.9, b = 26.4, c = 182.5 Å. This allowed the derivation of a new model for the arrangement of the triple-helical molecules in the crystals.

2010 ◽  
Vol 74 (1) ◽  
pp. 147-157 ◽  
Author(s):  
A. Garavelli ◽  
T. Balić-Žunić ◽  
D. Mitolo ◽  
P. Acquafredda ◽  
E. Leonardsen ◽  
...  

AbstractHeklaite, with the ideal formula KNaSiF6, was found among fumarolic encrustations collected in 1992 on the Hekla volcano, Iceland. Heklaite forms a fine-grained mass of micron- to sub-micron-sized crystals intimately associated with malladrite, hieratite and ralstonite. The mineral is colourless, transparent, non-fluorescent, has a vitreous lustre and a white streak. The calculated density is 2.69 g cm–3. An SEM-EDS quantitative chemical analysis shows the following range of concentrations (wt.%): Na 11.61–12.74 (average 11.98), K 17.02–18.97 (average 18.29), Si 13.48 –14.17 (average 13.91), F 54.88–56.19 (average 55.66). The empirical chemical formula, calculated on the basis of 9 a.p.f.u., is Na1.07K0.96Si1.01F5.97. X-ray powder diffraction indicates that heklaite is orthorhombic, space group Pnma, with the following unit-cell parameters: a = 9.3387(7) Å, b = 5.5032(4) Å, c = 9.7957(8) Å , V = 503.43(7) Å3, Z = 4. The eight strongest reflections in the powder diffraction pattern [d in Å (I/I0) (hkl)] are: 4.33 (53) (102); 4.26 (56) (111); 3.40 (49) (112); 3.37 (47) (202); 3.34 (100) (211); 2.251 (27) (303); 2.050 (52) (123); 2.016 (29) (321). On the basis of chemical analyses and X-ray data, heklaite corresponds to the synthetic compound KNaSiF6. The name is for the type locality, the Hekla volcano, Iceland.


Author(s):  
Michael R. Jackson ◽  
Thomas L. Selby

A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) fromStreptomyces antibioticushas been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space groupP222, with unit-cell parametersa= 41.26,b= 51.86,c = 154.78 Å. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 Å resolution.


Author(s):  
Peter-Thomas Naumann ◽  
Charles T. Lauhon ◽  
Ralf Ficner

The sulfurtransferase 4-thiouridine synthetase (ThiI) is involved in the ATP-dependent modification of U8 in tRNA. ThiI fromThermotoga maritimawas cloned, overexpressed and purified. A complex comprising ThiI and a truncated tRNA was prepared and crystallized, and X-ray diffraction data were collected to a resolution of 3.5 Å. The crystals belonged to the orthorhombic space groupP212121, with unit-cell parametersa= 102.9,b= 112.8,c= 132.8 Å.


2014 ◽  
Vol 70 (11) ◽  
pp. 1560-1562
Author(s):  
Guofang Zhang ◽  
Dan Yu ◽  
Guodong Yang ◽  
Hui Dong ◽  
Tongcun Zhang ◽  
...  

RPB_0146, a putative deaminase fromRhodopseudomonas palustrisHaA2, was expressed inEscherichia coliBL21 (DE3) cells and purified using a His6tag by Ni2+-chelating affinity chromatography for X-ray crystallographic analysis. Diffraction-quality crystals were grown by the hanging-drop vapour-diffusion method at 289 K and diffracted to a resolution of 2.44 Å using a wavelength of 1.000 Å at the Photon Factory (KEK), Japan. The crystals belonged to the orthorhombic space groupP212121, with unit-cell parametersa= 66.26,b= 123.94,c= 155.95 Å.


1999 ◽  
Vol 55 (8) ◽  
pp. 1471-1473 ◽  
Author(s):  
Domenico Bordo ◽  
Rita Colnaghi ◽  
Daniela Deriu ◽  
Aristodemo Carpen ◽  
Paola Storici ◽  
...  

The rhdA gene identified in Azotobacter vinelandii codes for a protein, RhdA, which displays rhodanese (thiosulfate–cyanide sulfurtransferase) activity. RhdA was overexpressed and purified to homogeneity. The protein crystallized in the orthorhombic space group P21212 with unit-cell parameters a = 44.4, b = 150.8, c = 53.8 Å; on a synchrotron source the diffraction patterns could be collected to a resolution limit of 1.8 Å. Evaluation of the crystal density indicates that the crystal lattice accommodates one molecule per asymmetric unit and that the solvent content is 59% of the total volume.


Author(s):  
Neta Tanner ◽  
Gali Prag

Members of the Epsin protein family regulate the ubiquitin/clathrin-dependent trafficking of transmembrane proteins. The yeast Epsin-1 (ent1) gene was cloned and expressed inEscherichia coli. The protein product of a construct containing the ENTH-UIM modules was purified to homogeneity and subjected to crystallization screening using the sitting-drop vapour-diffusion method. Refined conditions containing polyethylene glycol 3350 and Tacsimate yielded thin rod-like crystals. X-ray analysis revealed that the crystallographic symmetry is primitive orthorhombic, space groupP222, with unit-cell parametersa= 32.7,b= 35.5,c= 110.6 Å and a diffraction limit of 2.3 Å. Matthews coefficient calculations suggested that the crystal contained only the ENTH domain. This was corroborated by Coomassie Blue-stained SDS–PAGE analysis of dissolved crystals.


Author(s):  
Pilar Redondo ◽  
Nekane Merino ◽  
Maider Villate ◽  
Francisco J. Blanco ◽  
Guillermo Montoya ◽  
...  

Homing endonucleases are highly specific DNA-cleaving enzymes that recognize long stretches of DNA. The engineering of these enzymes provides novel instruments for genome modification in a wide range of fields, including gene targeting, by inducing specific double-strand breaks. I-CvuI is a homing endonuclease from the green algaChlorella vulgaris. This enzyme was purified after overexpression inEscherichia coli. Crystallization experiments of I-CvuI in complex with its DNA target in the presence of Mg2+yielded crystals suitable for X-ray diffraction analysis. The crystals belonged to the orthorhombic space groupP212121, with unit-cell parametersa= 62.83,b= 83.56,c= 94.40 Å. The self-rotation function and the Matthews coefficient suggested the presence of one protein–DNA complex per asymmetric unit. The crystals diffracted to a resolution limit of 1.9 Å using synchrotron radiation.


Author(s):  
Andrea Flores-Ibarra ◽  
Federico M. Ruiz ◽  
Sabine Vértesy ◽  
Sabine André ◽  
Hans-Joachim Gabius ◽  
...  

How lectins translate sugar-encoded information into cellular effects not only depends on glycan recognition. Other domains of the protein can contribute to the functional profile of a lectin. Human galectin-3 (Gal-3), an adhesion/growth-regulatory galectin, is composed of three different domains and is thus called a chimera-type protein. In addition to the carbohydrate-recognition domain, this lectin encompasses an N-terminal domain consisting of a peptide harbouring two phosphorylation sites and nine non-triple-helical collagen-like repeats. This region plays an as yet structurally undefined role in Gal-3 aggregation and ligand recognition. To date, crystallization of full-length Gal-3 has not been achieved. With the aim of providing structural insights into this modular organization, a Gal-3 variant was crystallized maintaining the terminal peptide and three of the nine collagen-like repeats. The crystals belonged to the orthorhombic space groupP212121, with unit-cell parametersa= 94.04,b= 97.96,c= 236.20 Å, and diffracted to a resolution of 3.3 Å.


2020 ◽  
Vol 28 (1) ◽  
pp. 219-223 ◽  
Author(s):  
Zdeněk Dolníček ◽  
Miroslav Nepejchal ◽  
Jiří Sejkora ◽  
Jana Ulmanová ◽  
Štěpán Chládek

Bohseite was found in a lenticular body of D6e beryl-columbite granitic pegmatite near Maršíkov, which is hosted by amphibole gneisses of the Sobotín Amphibolite Massif (Silesicum, northeastern part of Czech Republic). Bohseite forms chalky white aggregates up to 1 cm in size, which are hosted by small vugs in the coarse-grained pegmatite. It is associated with small crystals of quartz, adularia, albite, muscovite and epidote. Bohseite is orthorhombic, space group Cmcm with following unit-cell parameters refined from X-ray powder diffraction data: a 23.210(2), b 4.955(2), c 19.428(3) Å and V 2234.5(1.0) Å3. The electron microprobe compositional data of bohseite are presented. Bohseite from Maršíkov contains 14.3 - 42.5 mol. % of bavenite component, up to 0.06 apfu Na and 0.13 - 0.36 apfu F. The association with other beryllium-rich phases (milarite, bertrandite) points to variable activities of Be and Al during hydrothermal stage of evolution of the pegmatite body. The likely source of Be was beryl, which is sometimes completely dissolved and vugs after its crystals are lined by small crystals of above mentioned hydrothermal phases.


1988 ◽  
Vol 41 (9) ◽  
pp. 1305 ◽  
Author(s):  
JM Frederiksen ◽  
E Horn ◽  
MR Snow ◽  
ERT Tiekink

The crystal structures of the diastereoisomers formed between the hydrogen-D-tartrate anion and the cations (+)-(Λ-[Co(en)2(NO2)2]+ (1) and (-)-(Δ)-[Co(en)2(NO2)2]+ (2) have been determined by three-dimensional X-ray analysis. The crystal structures are comprised of octahedrally coordinated cobalt atoms, hydrogentartrate anions and water molecules interconnected by a complex hydrogen bonding network. In (1), columns of complex parallel to a 21 screw axis along a, are linked via hydrogen bonding contacts to a total of six chains of 'head-to-tail' hydrogentartrate strands. In contrast, in (2) the chains of hydrogentartrate anions associate with each other to form well defined 'walls' which sandwich hydrogen-bonded columns of complex cations such that the structure may be thought of as a layer structure of hydrogentartrate anions and complex cations. Crystals of both compounds are orthorhombic, space group P212121 with Z = 4, unit cell parameters for (1): a 7.670(1), b 12.160(1), c 18.028(1)Ǻ, V 1681.4 Ǻ3 and for (2): a 7.735(2), b 8.505(5), c 26.846(9) Ǻ, V 1766 1 Ǻ3. The structures were each refined by a full-matrix least-squares procedure to final R 0.026, Rw 0.027 for 1764 reflections with I ≥ 2.5σ(I) for (1) and R 0.065, Rw 0.073 for 1322 reflections for (2).


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