scholarly journals Purification, crystallization and preliminary X-ray diffraction studies of UDP-glucose:tetrahydrobiopterin α-glucosyltransferase (BGluT) fromSynechococcussp. PCC 7942

Author(s):  
Asaithambi Killivalavan ◽  
Ningning Zhuang ◽  
Young Shik Park ◽  
Kon Ho Lee

A UDP-glucose:tetrahydrobiopterin α-glucosyltransferase (BGluT) enzyme was discovered in the cyanobacteriumSynechococcussp. PCC 7942 which transfers a glucose moiety from UDP-glucose to tetrahydrobiopterin (BH4). BGluT protein was overexpressed with selenomethionine labelling for structure determination by the multi-wavelength anomalous dispersion method. The BGluT protein was purified by nickel-affinity and size-exclusion chromatography. It was then crystallized by the hanging-drop vapour-diffusion method using a well solution consisting of 0.1 Mbis-tris pH 5.5, 19%(w/v) polyethylene glycol 3350 with 4%(w/v) D(+)-galactose as an additive. X-ray diffraction data were collected to 1.99 Å resolution using a synchrotron-radiation source. The crystals belonged to the monoclinic space groupC2, with unit-cell parametersa= 171.35,b= 77.99,c = 53.77 Å, β = 90.27°.

Author(s):  
Xiao Zhang ◽  
Xi-Mei Xue ◽  
Yu Yan ◽  
Jun Ye

ArsH is an NADPH-dependent flavin mononucleotide reductase and is frequently encoded as part of anarsoperon. The function of thearsHgene remains to be characterized. Crystallization and structural studies may contribute to elucidating the specific biological function of ArsH associated with arsenic resistance. ArsH fromSynechocystissp. strain PCC 6803 was overproduced, purified and crystallized. Crystals were obtained by the sitting-drop vapour-diffusion method. Diffraction data were collected and processed to a resolution of 1.6 Å. The crystals belonged to the tetragonal space groupI4122, with unit-cell parametersa=b= 127.94,c= 65.86 Å and one molecule in the asymmetric unit. Size-exclusion chromatography and molecular-replacement results showed that the ArsH formed a tetramer. Further structural analysis and comparison with ArsH fromSinorhizobium melilotiwill provide information about the oligomerization of ArsH.


2015 ◽  
Vol 71 (8) ◽  
pp. 1038-1041
Author(s):  
Yang Song ◽  
Fan Zhang ◽  
Xu Li ◽  
Jianye Zang ◽  
Xuan Zhang

SarV, a member of the SarA protein family, is a global transcriptional regulator which has been reported to be involved in the regulation of autolysis inStaphylococcus aureus. In this study, SarV fromS. aureuswas successfully cloned, expressed, purified and crystallized. X-ray diffraction data were collected to 2.10 Å resolution. The crystals of SarV belonged to the monoclinic space groupP21, with unit-cell parametersa= 36.40,b= 119.64,c= 66.80 Å, α = γ = 90, β = 98.75°. The Matthews coefficient and the solvent content were estimated to be 2.57 Å3 Da−1and 52%, respectively, suggesting the presence of four molecules in the asymmetric unit. The results of size-exclusion chromatography (SEC) indicated thatS. aureusSarV exists as a homodimer in solution. Unfortunately, the structure cannot be solved by molecular replacement because of the low sequence identity ofS. aureusSarV to known structures. Further phase determination by selenomethionine single-wavelength anomalous dispersion (SAD) and the heavy-atom method is in progress.


2014 ◽  
Vol 70 (10) ◽  
pp. 1362-1367 ◽  
Author(s):  
Emmanuel Nji ◽  
Dianfan Li ◽  
Declan A. Doyle ◽  
Martin Caffrey

The prokaryotic lysine-specific permease (LysP) belongs to the amino acid–polyamine–organocation (APC) transporter superfamily. In the cell, members of this family are responsible for the uptake and recycling of nutrients, for the maintenance of a constant internal ion concentration and for cell volume regulation. The detailed mechanism of substrate selectivity and transport of L-lysine by LysP is not understood. A high-resolution crystal structure would enormously facilitate such an understanding. To this end, LysP fromPseudomonas aeruginosawas recombinantly expressed inEscherichia coliand purified to near homogeneity by immobilized metal ion-affinity chromatography (IMAC) and size-exclusion chromatography (SEC). Hexagonal- and rod-shaped crystals were obtained in the presence of L-lysine and the L-lysine analogue L-4-thialysine by vapour diffusion and diffracted to 7.5 Å resolution. The diffraction data were indexed in space groupP21, with unit-cell parametersa= 169.53,b= 169.53,c= 290.13 Å, γ = 120°.


2015 ◽  
Vol 71 (11) ◽  
pp. 1396-1400 ◽  
Author(s):  
Sze Lei Pang ◽  
Kok Lian Ho ◽  
Jitka Waterman ◽  
Aik-Hong Teh ◽  
Fook Tim Chew ◽  
...  

Dermatophagoides farinaeis one of the major house dust mite (HDM) species that cause allergic diseases. N-terminally His-tagged recombinant Der f 21 (rDer f 21), a group 21 allergen, with the signal peptide truncated was successfully overexpressed in anEscherichia coliexpression system. The purified rDer f 21 protein was initially crystallized using the sitting-drop vapour-diffusion method. Well diffracting protein crystals were obtained after optimization of the crystallization conditions using the hanging-drop vapour-diffusion method with a reservoir solution consisting of 0.19 MTris–HCl pH 8.0, 32% PEG 400 at 293 K. X-ray diffraction data were collected to 1.49 Å resolution using an in-house X-ray source. The crystal belonged to theC-centered monoclinic space groupC2, with unit-cell parametersa= 123.46,b= 27.71,c= 90.25 Å, β = 125.84°. The calculated Matthews coefficient (VM) of 2.06 Å3 Da−1suggests that there are two molecules per asymmetric unit, with a solvent content of 40.3%. Despite sharing high sequence identity with Blo t 5 (45%) and Blo t 21 (41%), both of which were determined to be monomeric in solution, size-exclusion chromatography, static light scattering and self-rotation function analysis indicate that rDer f 21 is likely to be a dimeric protein.


1999 ◽  
Vol 55 (4) ◽  
pp. 910-914 ◽  
Author(s):  
Michael M. Roberts ◽  
Alun R. Coker ◽  
Gianluca Fossati ◽  
Paolo Mascagni ◽  
Anthony R. M. Coates ◽  
...  

The Mycobacterium tuberculosis chaperonin 10 (Mtcpn10) has been crystallized by the sitting-drop vapour-diffusion method. The crystals belong to the monoclinic space group P21, with unit-cell parameters a = 76.5, b = 87.9, c = 124.4 Å, β = 106.8°. X-ray diffraction data were collected to 2.8 Å. The self-rotation function and the molecular-replacement solution show that the asymmetric unit contains a dimer of heptamers related by twofold non-crystallographic symmetry. The two heptamers interact through interleaving flexible loops in a similar fashion to M. leprae and Gp31 cpn10. In addition to its role in protein folding, Mtcpn10 has unique effects on the growth of host cells and is a major immunogen in tuberculosis infections. The structure determination will permit the analysis of the amino acids identified as important for the protein-folding and cell-signalling activity of Mtcpn10.


Author(s):  
Hyun Kim ◽  
Ae Kyung Park ◽  
Jun Hyuck Lee ◽  
Seung Chul Shin ◽  
Hyun Park ◽  
...  

Esterases are very useful biocatalysts in industry: they hydrolyze esters and split them into a carboxylic acid and an alcohol. The psychrophilic esterase PsEst3 was obtained from Paenibacillus sp. R4, which was isolated from the active layer of the permafrost in Council, Alaska. PsEst3 was successfully overexpressed using a psychrophilic chaperonin co-expression system and was purified by nickel-affinity and size-exclusion chromatography. Recombinant PsEst3 was crystallized at 290 K using the hanging-drop vapour-diffusion method. X-ray diffraction data were collected to 2.1 Å resolution. The crystal was determined to belong to space group P4132 or P4332, with unit-cell parameters a = b = c = 145.33 Å. Further crystallographic analysis needs to be conducted to investigate the structure and function of this esterase.


1999 ◽  
Vol 55 (11) ◽  
pp. 1920-1922 ◽  
Author(s):  
K. N. Rao ◽  
S. S. Hegde ◽  
R. J. Lewis ◽  
C. G. Suresh

A Bowman–Birk type trypsin/chymotrypsin inhibitor isolated from Vigna unguiculata seeds has been crystallized. Crystals were grown using the vapour-diffusion method at pH 4.0 using citrate/phosphate as a buffer and 30% saturated ammonium sulfate as precipitant. The crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 32.4, b = 61.8, c = 32.9 Å, β = 114.5°. The Matthews coefficient calculated assuming two molecules in the asymmetric unit was 1.95 Å3 Da−1, which corresponds to a 37% solvent content. X-ray data were collected to 2.5 Å resolution from a flash-frozen crystal. The structure was solved using the molecular-replacement method using tracy soybean inhibitor structure (PDB entry 1pi2) as a model.


Author(s):  
Srinivasan Rengachari ◽  
Philipp Aschauer ◽  
Christian Sturm ◽  
Monika Oberer

The protein Yju3p is the orthologue of monoglyceride lipases in the yeastSaccharomyces cerevisiae. A soluble variant of this lipase termed s-Yju3p (38.3 kDa) was generated and purified to homogeneity by affinity and size-exclusion chromatography. s-Yju3p was crystallized in a vapour-diffusion setup at 293 K and a complete data set was collected to 2.4 Å resolution. The crystal form was orthorhombic (space groupP212121), with unit-cell parametersa= 77.2,b= 108.6,c= 167.7 Å. The asymmetric unit contained four molecules with a solvent content of 46.4%.


Author(s):  
Yasumitsu Sakamoto ◽  
Yoshiyuki Suzuki ◽  
Ippei Iizuka ◽  
Chika Tateoka ◽  
Saori Roppongi ◽  
...  

Dipeptidyl aminopeptidase BII fromPseudoxanthomonas mexicanaWO24 (DAP BII) is able to cleave a variety of dipeptides from the amino-terminus of substrate peptides. For crystallographic studies, DAP BII was overproduced inEscherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. X-ray diffraction data to 2.3 Å resolution were collected using an orthorhombic crystal form belonging to space groupP212121, with unit-cell parametersa= 76.55,b= 130.86,c= 170.87 Å. Structural analysis by the multi-wavelength anomalous diffraction method is in progress.


Author(s):  
José Alberto Diogo ◽  
Leticia Maria Zanphorlin ◽  
Hélia Harumi Sato ◽  
Mario Tyago Murakami ◽  
Roberto Ruller

β-Xylosidases (EC 3.2.1.37) catalyze the hydrolysis of short xylooligosaccharides into xylose, which is an essential step in the complete depolymerization of xylan, the major hemicellulosic polysaccharide of plant cell walls, and has great biotechnological relevance for the production of lignocellulose-based biofuels and the paper industry. In this study, a GH43 β-xylosidase identified from the bacteriumBacillus licheniformis(BlXylA) was cloned into the the pET-28a bacterial expression vector, recombinantly overexpressed inEscherichia coliBL21(DE3) cells and purified to homogeneity by metal-affinity and size-exclusion chromatography. The protein was crystallized in the presence of the organic solvent 2-methyl-2,4-pentanediol and a single crystal diffracted to 2.49 Å resolution. The X-ray diffraction data were indexed in the monoclinic space groupC2, with unit-cell parametersa= 152.82,b= 41.9,c= 71.79 Å, β = 91.7°. Structural characterization of this enzyme will contribute to a better understanding of the structural requirements for xylooligosaccharide specificity within the GH43 family.


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