14 research outputs found
Purification, crystallization and preliminary crystallographic analysis of deoxyuridine triphosphate nucleotidohydrolase from Arabidopsis thaliana
The first crystallization of deoxyuridine triphosphate nucleotidohydrolase from plant, Arabidopsis thaliana, has been performed. An additive, taurine, was effective in producing the single crystal
Structural insights into the mechanism defining substrate affinity in Arabidopsis thaliana dUTPase: the role of tryptophan 93 in ligand orientation
Background: Deoxyuridine triphosphate nucleotidohydrolase (dUTPase) hydrolyzes dUTP to dUMP and pyrophosphate to maintain the cellular thymine-uracil ratio. dUTPase is also a target for cancer chemotherapy. However, the mechanism defining its substrate affinity remains unclear. Sequence comparisons of various dUTPases revealed that Arabidopsis thaliana dUTPase has a unique tryptophan at position 93, which potentially contributes to its degree of substrate affinity. To better understand the roles of tryptophan 93, A. thaliana dUTPase was studied.
Results: Enzyme assays showed that A. thaliana dUTPase belongs to a high-affinity group of isozymes, which also includes the enzymes from Escherichia coli and Mycobacterium tuberculosis. Enzymes from Homo sapiens and Saccharomyces cerevisiae are grouped as low-affinity dUTPases. The structure of the homo-trimeric A. thaliana dUTPase showed three active sites, each with a different set of ligand interactions between the amino acids and water molecules. On an α-helix, tryptophan 93 appears to keep serine 89 in place via a water molecule and to specifically direct the ligand. Upon being oriented in the active site, the C-terminal residues close the active site to promote the reaction.
Conclusions: In the high-affinity group, the prefixed direction of the serine residues was oriented by a positively charged residue located four amino acids away, while low-affinity enzymes possess small hydrophobic residues at the corresponding sites
Structural insights into the mechanism defining substrate affinity in Arabidopsis thaliana dUTPase: the role of tryptophan 93 in ligand orientation
Purification, crystallization and preliminary crystallographic analysis of deoxyuridine triphosphate nucleotidohydrolase from \u3ci\u3eArabidopsis thaliana\u3c/i\u3e
The deoxyuridine triphosphate nucleotidohydrolase gene from Arabidopsis thaliana was expressed and the gene product was purified. Crystallization was performed by the hanging-drop vapour-diffusion method at 298 K using 2 M ammonium sulfate as the precipitant. X-ray diffraction data were collected to 2.2 Å resolution using Cu Kα radiation. The crystal belongs to the orthorhombic space group P212121, with unit-cell parameters a = 69.90, b = 70.86 Å, c = 75.55 Å. Assuming the presence of a trimer in the asymmetric unit, the solvent content was 30%, with a VM of 1.8 Å3 Da-1
REPELLENT ACTION OF SEVIN PLANT EXTRACTS AGAINST TROGODERMA GRANARIUM (COLEOPTERA : DERMESTIDAE)
The pet. ether extract of species Cassia, Tridex, Parthenium, Dalbergia, Lawsonia, Eucalyptus, Aegle have been assessed for their repellent activity against Trogoderma granarium. Among these plant extracts cassia leaf extract exhibited highest repellent action whereas minimum repellent property was recorded in Aegle
Mechanical and geometric properties of thermoformed and 3D printed clear dental aligners
MOESM1 of Structural insights into the mechanism defining substrate affinity in Arabidopsis thaliana dUTPase: the role of tryptophan 93 in ligand orientation
Additional file 1: Figure S1. Effect of crystal packing on C-terminal residue coordinates
Mechanical behaviour of 3D printed vs thermoformed clear dental aligner materials under non-linear compressive loading using FEM
Clear dental aligners are commonly manufactured using thermoplastic materials such as Duran and Durasoft. Using conventional thermoforming methods there are inherent disadvantages including time consumption and poor geometrical accuracies that often occur. The use of digital technologies and 3D printing techniques for producing dental aligners is often preferred where possible. Innovation in 3D printing has resulted in bio-compatible materials becoming more readily available, including Formlabs Dental LT Clear resin, which is a 3D printable and Class IIa bio-compatible material. In this paper, we investigate the difference between thermoplastic materials such as Scheu-Dental Duran and Durasoft and 3D printed Dental LT using Finite Element Analysis (FEA)/Finite Element Modelling (FEM) in a dental aligner case based on an analysis of von Mises stress distribution at molars, incisors and canines for a total of 33161 nodes using Finite Element Analysis (FEA). Maximum von Mises stress distribution at all of the sections under the action of non-linear compressive forces equivalent to human biting force (up to 600 N) were discovered to vary within a range of 0.2–7.7% for Dental LT resin. The Duran and Durasoft cases were comparable, thereby widening the scope for the use of Dental LT in various dentistry applications, including clear aligners