scholarly journals Preliminary crystallographic analysis of a double mutant of the acetyl xylo-oligosaccharide esterase Axe2 in its dimeric form

2014 ◽  
Vol 70 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Shifra Lansky ◽  
Onit Alalouf ◽  
Rachel Salama ◽  
Hay Dvir ◽  
Yuval Shoham ◽  
...  
Keyword(s):  
Plant Cell Wall ◽  
Plant Biomass ◽  
Thermophilic Bacterium ◽  
Crystallographic Analysis ◽  
Dimensional Structure ◽  
Orthorhombic Space Group ◽  
Data Set ◽  
Cell Parameters ◽  
Wide Range ◽  
Dimeric Form

Xylans are polymeric sugars constituting a significant part of the plant cell wall. They are usually substituted with acetyl side groups attached at positions 2 or 3 of the xylose backbone units. Acetylxylan esterases are part of the hemicellulolytic system of many microorganisms which utilize plant biomass for growth. These enzymes hydrolyze the ester linkages of the xylan acetyl groups and thus improve the accessibility of main-chain-hydrolyzing enzymes and their ability to break down the sugar backbone units. The acetylxylan esterases are therefore critically important for those microorganisms and as such could be used for a wide range of biotechnological applications. The structure of an acetylxylan esterase (Axe2) isolated from the thermophilic bacteriumGeobacillus stearothermophilusT6 has been determined, and it has been demonstrated that the wild-type enzyme is present as a unique torus-shaped octamer in the crystal and in solution. In order to understand the functional origin of this unique oligomeric structure, a series of rational noncatalytic, site-specific mutations have been made on Axe2. Some of these mutations led to a different dimeric form of the protein, which showed a significant reduction in catalytic activity. One of these double mutants, Axe2-Y184F-W190P, has recently been overexpressed, purified and crystallized. The best crystals obtained belonged to the orthorhombic space groupP212121, with unit-cell parametersa= 71.1,b= 106.0,c= 378.6 Å. A full diffraction data set to 2.3 Å resolution has been collected from a flash-cooled crystal of this type at 100 K using synchrotron radiation. This data set is currently being used for the three-dimensional structure analysis of the Axe2-Y184F-W190P mutant in its dimeric form.

scholarly journals Crystallization and preliminary crystallographic analysis of Axe2, an acetylxylan esterase fromGeobacillus stearothermophilus

2013 ◽  
Vol 69 (4) ◽  
pp. 430-434 ◽  
Author(s):  
Shifra Lansky ◽  
Onit Alalouf ◽  
Vered Solomon ◽  
Anat Alhassid ◽  
Lata Govada ◽  
...  
Keyword(s):  
Diffraction Data ◽  
Biochemical Characterization ◽  
Plant Biomass ◽  
Crystallographic Analysis ◽  
Dimensional Structure ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
Data Set ◽  
Cell Parameters ◽  
Acetylxylan Esterase

Acetylxylan esterases are part of the hemi-cellulolytic system of many microorganisms which utilize plant biomass for growth. Xylans, which are polymeric sugars that constitute a significant part of the plant biomass, are usually substituted with acetyl side groups attached at position 2 or 3 of the xylose backbone units. Acetylxylan esterases hydrolyse the ester linkages of the xylan acetyl groups and thus improve the ability of main-chain hydrolysing enzymes to break down the sugar backbone units. As such, these enzymes play an important part in the hemi-cellulolytic utilization system of many microorganisms that use plant biomass for growth. Interest in the biochemical characterization and structural analysis of these enzymes stems from their numerous potential biotechnological applications. An acetylxylan esterase (Axe2) of this type fromGeobacillus stearothermophilusT-6 has recently been cloned, overexpressed, purified, biochemically characterized and crystallized. One of the crystal forms obtained (RB1) belonged to the tetragonal space groupI422, with unit-cell parametersa=b= 110.2,c= 213.1 Å. A full diffraction data set was collected to 1.85 Å resolution from flash-cooled crystals of the wild-type enzyme at 100 K using synchrotron radiation. A selenomethionine derivative of Axe2 has also been prepared and crystallized for single-wavelength anomalous diffraction experiments. The crystals of the selenomethionine-derivatized Axe2 appeared to be isomorphous to those of the wild-type enzyme and enabled the measurement of a full 1.85 Å resolution diffraction data set at the selenium absorption edge and a full 1.70 Å resolution data set at a remote wavelength. These data are currently being used for three-dimensional structure determination of the Axe2 protein.

scholarly journals Purification, crystallization and preliminary crystallographic analysis of Gan1D, a GH1 6-phospho-β-galactosidase fromGeobacillus stearothermophilusT1

2014 ◽  
Vol 70 (2) ◽  
pp. 225-231 ◽  
Author(s):  
Shifra Lansky ◽  
Arie Zehavi ◽  
Roie Dann ◽  
Hay Dvir ◽  
Hassan Belrhali ◽  
...  
Keyword(s):  
Plant Cell Wall ◽  
Extracellular Enzymes ◽  
Biochemical Characterization ◽  
Crystal Structure Analysis ◽  
Crystallographic Analysis ◽  
Glycoside Hydrolases ◽  
Cell Wall Polysaccharides ◽  
Data Set ◽  
Cell Parameters ◽  
Wide Range

Geobacillus stearothermophilusT1 is a Gram-positive thermophilic soil bacterium that contains an extensive system for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. The bacterium uses a number of extracellular enzymes that break down the high-molecular-weight polysaccharides into short oligosaccharides, which enter the cell and are further hydrolyzed into sugar monomers by dedicated intracellular glycoside hydrolases. The interest in the biochemical characterization and structural analysis of these proteins originates mainly from the wide range of their potential biotechnological applications. Studying the different hemicellulolytic utilization systems inG. stearothermophilusT1, a new galactan-utilization gene cluster was recently identified, which encodes a number of proteins, one of which is a GH1 putative 6-phospho-β-galactosidase (Gan1D). Gan1D has recently been cloned, overexpressed, purified and crystallized as part of its comprehensive structure–function study. The best crystals obtained for this enzyme belonged to the triclinic space groupP1, with average crystallographic unit-cell parameters ofa = 67.0,b= 78.1,c= 92.1 Å, α = 102.4, β = 93.5, γ = 91.7°. A full diffraction data set to 1.33 Å resolution has been collected for the wild-type enzyme, as measured from flash-cooled crystals at 100 K, using synchrotron radiation. These data are currently being used for the detailed three-dimensional crystal structure analysis of Gan1D.

scholarly journals Preliminary crystallographic analysis of Xyn52B2, a GH52 β-D-xylosidase fromGeobacillus stearothermophilusT6

2014 ◽  
Vol 70 (12) ◽  
pp. 1675-1682 ◽  
Author(s):  
Roie Dann ◽  
Shifra Lansky ◽  
Noa Lavid ◽  
Arie Zehavi ◽  
Valery Belakhov ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Crystal Form ◽  
Thermophilic Bacterium ◽  
Crystallographic Analysis ◽  
Dimensional Structure ◽  
Glycoside Hydrolase Family ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Cell Parameters ◽  
Average Unit

Geobacillus stearothermophilusT6 is a thermophilic bacterium that possesses an extensive hemicellulolytic system, including over 40 specific genes that are dedicated to this purpose. For the utilization of xylan, the bacterium uses an extracellular xylanase which degrades xylan to decorated xylo-oligomers that are imported into the cell. These oligomers are hydrolyzed by side-chain-cleaving enzymes such as arabinofuranosidases, acetylesterases and a glucuronidase, and finally by an intracellular xylanase and a number of β-xylosidases. One of these β-xylosidases is Xyn52B2, a GH52 enzyme that has already proved to be useful for various glycosynthesis applications. In addition to its demonstrated glycosynthase properties, interest in the structural aspects of Xyn52B2 stems from its special glycoside hydrolase family, GH52, the structures and mechanisms of which are only starting to be resolved. Here, the cloning, overexpression, purification and crystallization of Xyn52B2 are reported. The most suitable crystal form that has been obtained belonged to the orthorhombicP212121space group, with average unit-cell parametersa = 97.7,b= 119.1,c = 242.3 Å. Several X-ray diffraction data sets have been collected from flash-cooled crystals of this form, including the wild-type enzyme (3.70 Å resolution), the E335G catalytic mutant (2.95 Å resolution), a potential mercury derivative (2.15 Å resolution) and a selenomethionine derivative (3.90 Å resolution). These data are currently being used for detailed three-dimensional structure determination of the Xyn52B2 protein.

scholarly journals Expression, purification, crystallization and preliminary X-ray diffraction analysis of a type II NADH:quinone oxidoreductase from the human pathogenStaphylococcus aureus

2015 ◽  
Vol 71 (4) ◽  
pp. 477-482 ◽  
Author(s):  
Ana Lúcia Rosário ◽  
Filipa V. Sena ◽  
Ana P. Batista ◽  
Tânia F. Oliveira ◽  
Diogo Athayde ◽  
...  
Keyword(s):  
Drug Targets ◽  
Model Building ◽  
Type Ii ◽  
Orthorhombic Space Group ◽  
Data Set ◽  
Cell Parameters ◽  
Nadh:Quinone Oxidoreductase ◽  
Wide Range ◽  
Replacement Solution ◽  
Causative Agents

In recent years, type II NADH dehydrogenases (NDH-IIs) have emerged as potential drug targets for a wide range of human disease causative agents. In this work, the NDH-II enzyme from the Gram-positive human pathogenStaphylococcus aureuswas recombinantly expressed inEscherichia coli, purified, crystallized and a crystallographic data set was collected at a wavelength of 0.873 Å. The crystals belonged to the orthorhombic space groupP212121, with unit-cell parametersa= 81.8,b= 86.0,c= 269.9 Å, contained four monomers per asymmetric unit and diffracted to a resolution of 3.32 Å. A molecular-replacement solution was obtained and model building and refinement are currently under way.

Crystallization and preliminary crystallographic analysis of the hydroxyquinol 1,2-dioxygenase from Nocardioides simplex 3E: a novel dioxygenase involved in the biodegradation of polychlorinated aromatic compounds

1999 ◽  
Vol 55 (4) ◽  
pp. 901-903 ◽  
Author(s):  
Manuela Benvenuti ◽  
Fabrizio Briganti ◽  
Andrea Scozzafava ◽  
Ludmilla Golovleva ◽  
Vasily M. Travkin ◽  
...  
Keyword(s):  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Aerobic Biodegradation ◽  
Orthorhombic Space Group ◽  
Data Set ◽  
Cell Parameters ◽  
Peg 400 ◽  
Laboratory Source ◽  
Intradiol Cleavage ◽  
Intradiol Dioxygenase

Hydroxyquinol 1,2-dioxygenase (HQ1,2O) from Nocardioides simplex 3E, an enzyme involved in the aerobic biodegradation of a large class of chloroaromatic compounds such as 2,4-dichlorophenoxyacetate (2,4-D) and 2,4,5-trichlorophenoxyacetate (2,4,5-T), has been crystallized. HQ1,2O, which specifically catalyzes the intradiol cleavage of hydroxyquinol (1,2,4-trihydroxybenzene), an intermediate in the degradation of a variety of aromatic pollutants, to maleylacetate, has been recently purified to homogeneity. The enzyme is an homodimer composed of two identical subunits in a α2-type quaternary structure, has a molecular weight of about 65 kDa and contains a catalytically essential Fe(III) ion. Crystals of HQ1,2O obtained using 2% PEG 400 and 2 M ammonium sulfate at pH 7.5 as precipitants belong to the orthorhombic space group P212121, with unit-cell parameters a = 81.15 (6), b = 86.79 (7), c = 114.93 (8). Assuming one dimer per asymmetric unit, the Vm value is 2.51 Å3 Da−1. A complete native data set to 1.8 Å resolution has been collected on a laboratory source. This is the first intradiol dioxygenase which specifically catalyzes the cleavage of hydroxyquinol to give diffraction-quality crystals.

scholarly journals Crystallization and preliminary X-ray crystallographic analysis of PBPD2 fromListeria monocytogenes

2014 ◽  
Vol 70 (4) ◽  
pp. 535-537 ◽  
Author(s):  
Hyung Jin Cha ◽  
Jae-Hee Jeong ◽  
Yeon-Gil Kim
Keyword(s):  
Biosynthetic Pathway ◽  
Crystallographic Analysis ◽  
Diffusion Method ◽  
Low Molecular Weight ◽  
Molecular Replacement ◽  
Orthorhombic Space Group ◽  
Penicillin Binding Proteins ◽  
Cell Parameters ◽  
Replacement Method ◽  
Molecular Replacement Method

Penicillin-binding proteins (PBPs), which mediate the peptidoglycan biosynthetic pathway in the bacterial cell wall, have been intensively investigated as a target for the design of antibiotics. In this study, PBPD2, a low-molecular-weight PBP encoded bylmo2812fromListeria monocytogenes, was overexpressed inEscherichia coli, purified and crystallized at 295 K using the sitting-drop vapour-diffusion method. The crystal belonged to the primitive orthorhombic space groupP212121, with unit-cell parametersa= 37.7,b= 74.7,c= 75.1 Å, and diffracted to 1.55 Å resolution. There was one molecule in the asymmetric unit. The preliminary structure was determined by the molecular-replacement method.

scholarly journals YopT domain of the PfhB2 toxin from Pasteurella multocida: protein expression, characterization, crystallization and crystallographic analysis

2018 ◽  
Vol 74 (3) ◽  
pp. 128-134
Author(s):  
Sanjeev Kumar ◽  
Victoria Hedrick ◽  
Seema Mattoo
Keyword(s):  
Pasteurella Multocida ◽  
Opportunistic Infections ◽  
Structural Information ◽  
Sequence Similarity ◽  
Catalytic Triad ◽  
Crystallographic Analysis ◽  
High Sequence Similarity ◽  
Data Set ◽  
Cell Parameters ◽  
Tract Infections

Pasteurella multocida causes respiratory-tract infections in a broad range of animals, as well as opportunistic infections in humans. P. multocida secretes a multidomain toxin called PfhB2, which contains a YopT-like cysteine protease domain at its C-terminus. The YopT domain of PfhB2 contains a well conserved Cys–His–Asp catalytic triad that defines YopT family members, and shares high sequence similarity with the prototype YopT from Yersinia sp. To date, only one crystal structure of a YopT family member has been reported; however, additional structural information is needed to help characterize the varied substrate specificity and enzymatic action of this large protease family. Here, a catalytically inactive C3733S mutant of PfhB2 YopT that provides enhanced protein stability was used with the aim of gaining structural insight into the diversity within the YopT protein family. To this end, the C3733S mutant of PfhB2 YopT has been successfully cloned, overexpressed, purified and crystallized. Diffraction data sets were collected from native crystals to 3.5 Å resolution and a single-wavelength anomalous data set was collected from an iodide-derivative crystal to 3.2 Å resolution. Data pertaining to crystals belonging to space group P31, with unit-cell parameters a = 136.9, b = 136.9, c = 74.7 Å for the native crystals and a = 139.2, b = 139.2, c = 74.7 Å for the iodide-derivative crystals, are discussed.

scholarly journals Purification, crystallization and preliminary crystallographic analysis of a 4-thiouridine synthetase–RNA complex

2013 ◽  
Vol 69 (4) ◽  
pp. 421-424 ◽  
Author(s):  
Peter-Thomas Naumann ◽  
Charles T. Lauhon ◽  
Ralf Ficner
Keyword(s):  
Diffraction Data ◽  
Thermotoga Maritima ◽  
Crystallographic Analysis ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Dependent Modification ◽  
Rna Complex

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.

scholarly journals Ribokinase fromLeishmania donovani: purification, characterization and X-ray crystallographic analysis

2018 ◽  
Vol 74 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Santhosh Gatreddi ◽  
Sayanna Are ◽  
Insaf Ahmed Qureshi
Keyword(s):  
Functional Characterization ◽  
Three Dimensional ◽  
Protozoan Parasite ◽  
Crystallographic Analysis ◽  
Size Exclusion ◽  
Dimensional Structure ◽  
Diffusion Method ◽  
Gene Encoding ◽  
Cell Parameters ◽  
Α Helix

Leishmaniais an auxotrophic protozoan parasite which acquires D-ribose by transporting it from the host cell and also by the hydrolysis of nucleosides. The enzyme ribokinase (RK) catalyzes the first step of ribose metabolism by phosphorylating D-ribose using ATP to produce D-ribose-5-phosphate. To understand its structure and function, the gene encoding RK fromL. donovaniwas cloned, expressed and purified using affinity and size-exclusion chromatography. Circular-dichroism spectroscopy of the purified protein showed comparatively more α-helix in the secondary-structure content, and thermal unfolding revealed theTmto be 317.2 K. Kinetic parameters were obtained by functional characterization ofL. donovaniRK, and theKmvalues for ribose and ATP were found to be 296 ± 36 and 116 ± 9.0 µM, respectively. Crystals obtained by the hanging-drop vapour-diffusion method diffracted to 1.95 Å resolution and belonged to the hexagonal space groupP61, with unit-cell parametersa=b= 100.25,c= 126.77 Å. Analysis of the crystal content indicated the presence of two protomers in the asymmetric unit, with a Matthews coefficient (VM) of 2.45 Å3 Da−1and 49.8% solvent content. Further study revealed that human counterpart of this protein could be used as a template to determine the first three-dimensional structure of the RK from trypanosomatid parasites.

scholarly journals Production, crystallization and preliminary crystallographic analysis ofAllochromatium vinosumthiosulfate dehydrogenase TsdA, an unusual acidophilicc-type cytochrome

2014 ◽  
Vol 70 (10) ◽  
pp. 1424-1427 ◽  
Author(s):  
José A. Brito ◽  
André Gutierres ◽  
Kevin Denkmann ◽  
Christiane Dahl ◽  
Margarida Archer
Keyword(s):  
Crystallographic Analysis ◽  
Sulfur Cycle ◽  
Monoclinic Space Group ◽  
Asymmetric Unit ◽  
Oxidative Condensation ◽  
Unit Cell Parameters ◽  
Allochromatium Vinosum ◽  
Data Set ◽  
Purple Sulfur Bacterium ◽  
Cell Parameters

The ability to perform the very simple oxidation of two molecules of thiosulfate to tetrathionate is widespread among prokaryotes. Despite the prevalent occurrence of tetrathionate formation and its well documented significance within the sulfur cycle, little is known about the enzymes that catalyze the oxidative condensation of two thiosulfate anions. To fill this gap, the thiosulfate dehydrogenase (TsdA) enzyme from the purple sulfur bacteriumAllochromatium vinosumwas recombinantly expressed inEscherichia coli, purified and crystallized, and a crystallographic data set was collected. The crystals belonged to the monoclinic space groupC2, with unit-cell parametersa= 79.2,b= 69.9,c= 57.9 Å, β = 129.3°, contained one monomer per asymmetric unit and diffracted to a resolution of 1.98 Å.

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