scholarly journals Crystallization and preliminary X-ray characterization of the eukaryotic replication terminator Reb1–Ter DNA complex

2015 ◽  
Vol 71 (4) ◽  
pp. 414-418 ◽  
Author(s):  
Rahul Jaiswal ◽  
Samarendra K. Singh ◽  
Deepak Bastia ◽  
Carlos R. Escalante
Keyword(s):  
Replication Fork ◽  
Structural Information ◽  
Transcription Termination ◽  
Replication Forks ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Naturally Occurring ◽  
Dna Complex

The Reb1 protein fromSchizosaccharomyces pombeis a member of a family of proteins that control programmed replication termination and/or transcription termination in eukaryotic cells. These events occur at naturally occurring replication fork barriers (RFBs), where Reb1 binds to termination (Ter) DNA sites and coordinates the polar arrest of replication forks and transcription approaching in opposite directions. The Reb1 DNA-binding and replication-termination domain was expressed inEscherichia coli, purified and crystallized in complex with a 26-mer DNA Ter site. Batch crystallization under oil was required to produce crystals of good quality for data collection. Crystals grew in space groupP21, with unit-cell parametersa= 68.9,b= 162.9,c= 71.1 Å, β = 94.7°. The crystals diffracted to a resolution of 3.0 Å. The crystals were mosaic and required two or three cycles of annealing. This study is the first to yield structural information about this important family of proteins and will provide insights into the mechanism of replication and transcription termination.

scholarly journals STRUCTURAL CHARACTERIZATION OF THE NEW DIAMOND-LIKE SEMICONDUCTOR CuNbGaSe3

2018 ◽  
Vol 15 (29) ◽  
pp. 228-233
Author(s):  
J. A. FLORES-CRUZ ◽  
G. E. DELGADO ◽  
J. E. CONTRERAS ◽  
M. QUINTERO ◽  
L. NIEVES ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Behavior ◽  
Secondary Phase ◽  
Chalcopyrite Structure ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Chalcogenide Compound ◽  
Semiconductor Type

The chalcogenide compound CuNbGaSe3, belonging to the system I-II-III-VI3, has been investigated by means of X-ray powder diffraction and its crystal structure has been refined by the Rietveld method.This is a material of the semiconductor type, which improves the properties of a simple semiconductor like CuGaSe2 because it ads spintronic applications due to its magnetic behavior. The powder pattern was composed by 94.2% of the principal phase CuNbGaSe3 and 5.8% of the secondary phase Cu0.667NbSe2. This material crystallizes with a CuFeInSe3-type structure in the tetragonal space group P4 2c (Nº 112), unit cell parameters a = 5.6199(4) Å, c = 11.0275(2) Å, V = 348.28(4) Å3, with a normal adamantane-structure where occurs a degradation of symmetry from the chalcopyrite structure I4 2d to a related structure P4 2c.

Structural characterization of dimercury(1+) pentacyanonitrosylferrate(2−), Hg2[Fe(CN)5NO]

2000 ◽  
Vol 15 (3) ◽  
pp. 193-197
Author(s):  
V. Venegas ◽  
G. Rueda-Morales ◽  
E. Reguera ◽  
F. Caleyo
Keyword(s):  
Atomic Force Microscopy ◽  
Orthorhombic Symmetry ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Force Microscopy ◽  
Atomic Force ◽  
Density Values

The titled compound, Hg2[Fe(CN)5NO], was synthesized and studied by X-ray powder diffraction, infrared spectroscopy, Mössbauer spectroscopy, and atomic force microscopy. The results arising from this study indicate that this compound is anhydrous and crystallizes in the P222 orthorhombic symmetry. The unit cell parameters were quantified as a=16.5905(9) Å, b=12.3145(8) Å, and c=8.7576(5) Å. The measured and calculated density values are Dm=1.149 g/cm3 and Dc=1.145 g/cm3, respectively, with Z=2.

Magnesio-riebeckite from the Varenche mine (Aosta Valley, Italy): crystal-chemical characterization of a grandfathered end-member

2017 ◽  
Vol 81 (6) ◽  
pp. 1431-1437 ◽  
Author(s):  
Roberta Oberti ◽  
Massimo Boiocchi ◽  
Frank C. Hawthorne ◽  
Marco E. Ciriotti
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Structure Refinement ◽  
Chemical Characterization ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
D Values

AbstractMagnesio-riebeckite from the dumps of the abandoned mine of Varenche (45°47’22’’ N, 7°29’17’’ E), Saint-Barthélemy, Nus, Aosta Valley (Italy), was studied to provide the complete mineral description (including crystal structure) and insights into the crystal-chemistry of riebeckite. The empirical formula derived from electron microprobe analysis and single-crystal structure refinement is A(Na0.09K0.01)Σ=0.10B(Na1.77Ca0.11Mg0.08Mn2+ 0:04)Σ=2.00C(Mg2.93Mn2+0:13Fe2+0:07Zn0.01Ni0.12Fe3+1:25Al0.48Ti0.01)Σ=5.00T(Si7.92Al0.08)Σ=8.00 O22W(OH1.88F0.12)Σ=2.00. Magnesio-riebeckite is biaxial (+), with α = 1.678(2), β = 1.682(2), γ = 1.688(2) and 2V (meas.) = 80.2(1.7)°, 2V (calc.) = 78.7°. The unit-cell parameters are a = 9.6481(14), b = 17.873(3), c = 5.3013(7) Å, β = 103.630(2)°, V = 888.4 (2)Å3, Z = 2, space group C2/m. The strongest ten reflections in the powder X-ray pattern [d values (in Å), I, (hkl)] are: 2.701, 100, (151); 8.303, 83, (110); 3.079, 62, (310); 3.391, 53, (131); 4.467, 50, (040,021); 2.522, 50, (̅202); 2.578, 35, (061); 2.155, 30, (261), 4.855, 30, (̅111), 2.300, 29, (̅351).

scholarly journals Crystallization and preliminary X-ray analysis of two variants of theEscherichia coliO157 ParE2–PaaA2 toxin–antitoxin complex

2014 ◽  
Vol 70 (9) ◽  
pp. 1284-1291 ◽  
Author(s):  
Yann G. J. Sterckx ◽  
Sarah Haesaerts ◽  
Laurence Van Melderen ◽  
Remy Loris
Keyword(s):  
Gel Filtration ◽  
Unit Cell ◽  
Full Length ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
X Ray Scattering ◽  
Complex Forms

ThepaaR2–paaA2–parE2operon is a three-component toxin–antitoxin module encoded in the genome of the human pathogenEscherichia coliO157. The toxin (ParE2) and antitoxin (PaaA2) interact to form a nontoxic toxin–antitoxin complex. In this paper, the crystallization and preliminary characterization of two variants of the ParE2–PaaA2 toxin–antitoxin complex are described. Selenomethionine-derivative crystals of the full-length ParE2–PaaA2 toxin–antitoxin complex diffracted to 2.8 Å resolution and belonged to space groupP41212 (orP43212), with unit-cell parametersa=b= 90.5,c= 412.3 Å. It was previously reported that the full-length ParE2–PaaA2 toxin–antitoxin complex forms a higher-order oligomer. In contrast, ParE2 and PaaA213–63, a truncated form of PaaA2 in which the first 12 N-terminal residues of the antitoxin have been deleted, form a heterodimer as shown by analytical gel filtration, dynamic light scattering and small-angle X-ray scattering. Crystals of the PaaA213–63–ParE2 complex diffracted to 2.7 Å resolution and belonged to space groupP6122 (orP6522), with unit-cell parametersa=b= 91.6,c= 185.6 Å.

scholarly journals Purification and X-ray crystallographic analysis of 7-keto-8-aminopelargonic acid (KAPA) synthase fromMycobacterium smegmatis

2014 ◽  
Vol 70 (10) ◽  
pp. 1372-1375 ◽  
Author(s):  
Shanghua Fan ◽  
Defeng Li ◽  
Joy Fleming ◽  
Yuan Hong ◽  
Tao Chen ◽  
...  
Keyword(s):  
Crystallographic Analysis ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Essential Enzyme ◽  
Mycobacterial Growth

7-Keto-8-aminopelargonic acid synthase (KAPA synthase; BioF) is an essential enzyme for mycobacterial growth that catalyses the first committed step in the biotin-synthesis pathway. It is a pyridoxal 5′-phosphate (PLP)-dependent enzyme and is a potential drug target. Here, the cloning, expression, purification and crystallization of KAPA synthase fromMycobacterium smegmatis(MsBioF) and the characterization of MsBioF crystals using X-ray diffraction are described. The crystals diffracted to 2.3 Å resolution and belonged to the monoclinic space groupP21, with unit-cell parametersa= 70.88,b= 91.68,c= 109.84 Å, β = 97.8°. According to the molecular weight of MsBioF, the unit-cell parameters and the self-rotation function map, four molecules are present in each asymmetric unit with aVMvalue of 2.06 Å3 Da−1and a solvent content of 40.20%.

Conventional synthesis and characterization of rare earth doped barium borophosphates, BaBPO5:RE (Y, Gd and La)

2016 ◽  
Vol 81 (2) ◽  
pp. 49-54
Author(s):  
G. Çelik Gül ◽  
F. Kurtuluş
Keyword(s):  
Rare Earth ◽  
Synthesis Method ◽  
Unit Cell ◽  
Synthesis And Characterization ◽  
Dihydrogen Phosphate ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Rare Earth Doped

Purpose: of this research, our target is synthesis and characterization of rare earth metalssuch as Y, Gd and La doped barium borophosphate compounds which are applicable innon-linear optics industry.Design/methodology/approach: The starting materials rare earth oxides, bariumcarbonate, boric acid and ammonium dihydrogen phosphate as analytically grade weighed0.01:1:1:1 molar ratio and homogenized in an agate mortar. The mixture placed into aporcelain crucible to heat in high temperature oven step by step. First, mixtures were waitedat 400°C for 2 hours for calcination process, subsequently heated 900°C with step rate10°C/m for 8 hours, and finally cooled down to room temperature with step rate 10°C/m.After many grindings final product get ready for characterization. X-ray powder diffraction(XRD) analysis was performed using PANanalytical X’Pert PRO Diffractometer (XRD) withCu Kα (1.5406 Å, 45 kV and 30 mA) radiation. Fourier transform infrared spectroscopy(FTIR) was taken on a Perkin Elmer Spectrum 100 FTIR Spectrometer from 4000 to 650cm-1. Scanning electron microscopy was achieved in SEM JEOL 6390-LV. Luminescenceproperties were performed by Andor Solis Sr 500i spectrophotometer. Conventional solidstate syntheses were done in Protherm furnace.Findings: The powder XRD patterns of the samples show that there is no impurity related todoping materials mean all diffractions corresponding to host material barium borophosphatecrystallized in hexagonal system with unit cell parameters a=7.1003 and c=6.9705 Å. Theunit cell parameters of rare earth doped barium borophosphates were calculated and displayboth increase and decrease depends on ionic Radius of rare earths. The other supportingmethods confirm the crystal structure and luminescence properties.Research limitations/implications: The synthesis method has some disadvantagessuch as low homogeneity, non-uniform product etc. We tried to minimize these negativeaspects in our research and succeeded.Practical implications: Phosphor materials Y:BaBPO5, Gd:BaBPO5 and La:BaBPO5(ICSD 51171) were synthesized by conventional solid state method and characterizationswas mainly based on powder X-ray diffraction pattern. Also, morphological and luminescenceproperties were completed to get the highest knowledge.Originality/value: Of the paper is first time conventional synthesis of Y, Gd and La dopedBaBPO5 compounds, calculation of unit cell parameters, and investigation of morphologicaland luminescent properties.

Hydrothermal synthesis and characterization of the praseodymium borate-nitrate Pr[B5O8(OH)(H2O)0.87]NO3·2H2O

2017 ◽  
Vol 72 (9) ◽  
pp. 677-685
Author(s):  
Teresa S. Ortner ◽  
Hubert Huppertz
Keyword(s):  
Hydrothermal Synthesis ◽  
Synthesis And Characterization ◽  
The Novel ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Rare Earth Borate ◽  
Ir And Raman

AbstractThe praseodymium borate-nitrate Pr[B5O8(OH)(H2O)0.87]NO3·2H2O was obtained in a hydrothermal synthesis. It crystallizes monoclinically in the space groupP21/n(no. 14) with four formula units (Z=4) and unit cell parameters ofa=641.9(3),b=1551.8(7),c=1068.4(5) pm, withβ=90.54(2)° yieldingV=1.0643(8) nm3. The defect variant constitutes the missing member in the series of isostructural, early rare earth borate-nitrates of the compositionRE[B5O8(OH)(H2O)x]NO3·2H2O [RE=La (x=0; 1), Ce (x=1), Nd (x=0.85), Sm (x=0)]. In addition to powder and single-crystal X-ray diffraction data, the novel borate-nitrate was characterized through IR and Raman spectroscopy.

Synthesis and characterization of a new trimetallic compound (NH4)Ni2.4Co0.6O(OH)(MoO4)2•1.5H2O

2014 ◽  
Vol 29 (4) ◽  
pp. 379-382 ◽  
Author(s):  
Sandra Amaya ◽  
Johana Arboleda ◽  
Adriana Echavarría
Keyword(s):  
Thermal Analysis ◽  
Laser Raman Spectroscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Laser Raman ◽  
Fourier Transformed Infrared Spectroscopy

A new trimetallic compound with formula (NH4)Ni2.4Co0.6O(OH)(MoO4)2•1.5H2O was obtained by hydrothermal synthesis. The solid was characterized by X-ray diffraction, thermal analysis (thermogravimetric analysis and differential thermal analysis), Fourier-transformed infrared spectroscopy, Laser Raman spectroscopy, and chemical analysis by atomic absorption, confirming the formation of the layered phase ϕy. Crystallographic studies showed that the compound obtained is trigonal with hexagonal unit-cell parameters, a = 6.0468 ± 0.0016 Å and c = 21.8433 ± 0.0001 Å, and space group R-3m.

scholarly journals Synthesis, Crystal Structures and Characterization of Two Nonmetal Cation Tetrafluoroborates

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 812
Author(s):  
Noura Othman Alzamil ◽  
Ghareeba Mussad Al-Enzi ◽  
Aishah Hassan Alamri ◽  
Insaf Abdi ◽  
Amor BenAli
Keyword(s):  
Thermal Analysis ◽  
Hydrofluoric Acid ◽  
Cell Parameter ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Microwave Assisted

Two new nonmetal cation tetrafluoroborate phases [H3tren](BF4)3 (I) and [H3tren](BF4)3 HF (II) were synthesized by microwave-assisted solvothermal and characterized by single crystal X-ray diffraction, IR spectroscopy and thermal analysis DTA-TGA. [H3tren](BF4)3 is cubic (P213) with unit cell parameter a = 11.688(1) Å. [H3tren](BF4)3•HF is trigonal (R3c) with unit cell parameters a = 15.297(6) Å and c = 12.007(2) Å. Both (I) and (II) structures can be described from isolated tetrafluoroborate BF4- anions, triprotonated tris-(2-aminoethyl)amine (tren) [H3tren]3+. Phase (II) contains disordered BF4- tetrahedron and hydrofluoric acid.

Synthesis and Characterization of A2CaCuO5(A=Nd, Sm)

1998 ◽  
Vol 12 (11) ◽  
pp. 427-431
Author(s):  
K. Jeyabalan ◽  
L. K. Kaliyaperumal ◽  
A. Sekar ◽  
J. Srinivas
Keyword(s):  
Diffraction Analysis ◽  
Unit Cell ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Cell Parameters

Synthesis and characterization of A 2 CaCuO 5( A=Nd, Sm ) system is reported. Powder X-ray diffraction analysis shows that the compounds crystallizes in an orthorhombic crystal systems and the unit cell parameters are found to be a=6.399(9)Å, b=7.218(8) Å and c=12.167(17) Å for Nd 2 CaCuO 5 and a=5.872(8) Å, b=7.457(3) Å and c=12.682(18) Å for Sm 2 CaCuO 5.

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