scholarly journals Biochemical Characterization of RecBCD Enzyme from An AntarcticPseudomonasSpecies and Identification of Its Cognate Chi (χ) Sequence

2018 ◽  
Author(s):  
Theetha L. Pavankumar ◽  
Anurag Kumar Sinha ◽  
Malay K. Ray
Keyword(s):  
Low Temperature ◽  
Pseudomonas Syringae ◽  
Biochemical Characterization ◽  
Uv Light ◽  
Ultra Violet ◽  
Nuclease Activity ◽  
Strand Break ◽  
Luria Bertani ◽  
Cold Sensitivity ◽  
Recbcd Enzyme

ABSTRACTPseudomonas syringaeLz4W RecBCD enzyme, RecBCDPs, is a trimeric protein complex comprised of RecC, RecB, and RecD subunits. RecBCD enzyme is essential forP. syringaegrowth at low temperature, and it protects cells from low temperature induced replication arrest. In this study, we show that the RecBCDPsenzyme displays distinct biochemical behaviors. UnlikeE. coliRecBCD enzyme, the RecD subunit is indispensable for RecBCDPsfunction. The RecD motor activity is essential for the Chi-like fragments production inP. syringae, highlighting a distinct role forP. syringaeRecD subunit in DNA repair and recombination process. Further, the ssDNA-dependent endonuclease activity is notably absent in RecBCDPsenzyme. Here, we demonstrate that the RecBCDPsenzyme recognizes a unique octameric DNA sequence, 5′-GCTGGCGC-3′ (ChiPs) that attenuates nuclease activity of the enzyme when it enters dsDNA from the 3′-end. We propose that the reduced translocation activities manifested by motor-defective mutants cause cold sensitivity inP. syrinage; emphasizing the importance of DNA processing and recombination functions in rescuing low temperature induced replication fork arrest.Abbreviations:ATPAdenosine triphosphateDSBdouble-strand break‘ChiCrossover hotspot instigatorNi-NTANitrio tri-acetic acidTLCthin layer chromatographyMMCmitomycin CUV lightUltra violetABMAntarctic bacterial mediumLBLuria-Bertani medium

scholarly journals Mre11 and Rad50 from Pyrococcus furiosus: Cloning and Biochemical Characterization Reveal an Evolutionarily Conserved Multiprotein Machine

2000 ◽  
Vol 182 (21) ◽  
pp. 6036-6041 ◽  
Author(s):  
Karl-Peter Hopfner ◽  
Annette Karcher ◽  
David Shin ◽  
Cecilia Fairley ◽  
John A. Tainer ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Pyrococcus Furiosus ◽  
Nuclease Activity ◽  
Strand Break ◽  
Biochemical Properties ◽  
Critical Event ◽  
Stable Complex ◽  
Nucleic Acid Metabolism ◽  
Dna Double Strand Breaks ◽  
Thermophilic Archaeon

ABSTRACT The processing of DNA double-strand breaks is a critical event in nucleic acid metabolism. This is evidenced by the severity of phenotypes associated with deficiencies in this process in multiple organisms. The core component involved in double-strand break repair in eukaryotic cells is the Mre11-Rad50 protein complex, which includes a third protein, p95, in humans and Xrs2 in yeasts. Homologues of Mre11 and Rad50 have been identified in all kingdoms of life, while the Nbs1 protein family is found only in eukaryotes. In eukaryotes the Mre11-Rad50 complex has nuclease activity that is modulated by the addition of ATP. We have isolated the Mre11 and Rad50 homologues from the thermophilic archaeon Pyrococcus furiosus and demonstrate that the two proteins exist in a large, heat-stable complex that possesses single-strand endonuclease activity and ATP-dependent double-strand-specific exonuclease activity. These findings verify the identification of the P. furiosus Rad50 and Mre11 homologues and demonstrate that functional homologues with similar biochemical properties exist in all kingdoms of life.

Biochemical Characterization of a Mutant recBCD Enzyme, the recB2109CD Enzyme, Which Lacks χ-specific, but Not Non-specific, Nuclease Activity

1993 ◽  
Vol 231 (3) ◽  
pp. 605-620 ◽  
Author(s):  
Angela K. Eggleston ◽  
Stephen C. Kowalczykowski
Keyword(s):  
Biochemical Characterization ◽  
Nuclease Activity ◽  
Recbcd Enzyme

scholarly journals All Three Subunits of RecBCD Enzyme Are Essential for DNA Repair and Low-Temperature Growth in the Antarctic Pseudomonas syringae Lz4W

PLoS ONE ◽  
2010 ◽  
Vol 5 (2) ◽  
pp. e9412 ◽  
Author(s):  
Theetha L. Pavankumar ◽  
Anurag K. Sinha ◽  
Malay K. Ray
Keyword(s):  
Dna Repair ◽  
Low Temperature ◽  
Pseudomonas Syringae ◽  
Temperature Growth ◽  
Low Temperature Growth ◽  
Recbcd Enzyme ◽  
The Antarctic

Green Synthesis of Copper Oxide Nanoparticles using Cucumis sativus (cucumber) Extracts and their Bio-physical and Biochemical Characterization for Cosmetic and Dermatologic Applications

2020 ◽  
Vol 20 ◽  
Author(s):  
Monika Vats ◽  
Shruti Bhardwaj ◽  
Arvind Chhabra
Keyword(s):  
Copper Oxide ◽  
Green Synthesis ◽  
Biochemical Characterization ◽  
Chemical Characterization ◽  
Ultra Violet ◽  
Skin Penetration ◽  
Copper Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Ultra Violet Radiation ◽  
Anti Fungal

Background & Objective: Nanoparticles are used in cosmetic and dermatologic products, due to better skin penetration properties. Incorporation of natural products exhibiting medicinal properties in nano-preparations could significantly improve efficacy of these products and improve the quality of life without the side effects of synthetic formulations. Methods: We here report green synthesis of Copper Oxide nanoparticles, using Cucumber extract, and their detailed biophysical and bio-chemical characterization. Results: These Copper Oxide-Cucumber nanoparticles exhibit significant anti-bacterial and anti-fungal properties, Ultra Violet-radiation protection ability and reactive-oxygen species inhibition properties. Importantly, these nanoparticles do not exhibit significant cellular toxicity and, when incorporated in skin cream, exhibit skin rejuvenating properties. Conclusion: Our findings have implications for nanoparticle-based cosmetics and dermatologic applications.

scholarly journals Effect of Pre-Harvest Supplemental UV-A/Blue and Red/Blue LED Lighting on Lettuce Growth and Nutritional Quality

Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 80
Author(s):  
Triston Hooks ◽  
Joseph Masabni ◽  
Ling Sun ◽  
Genhua Niu
Keyword(s):  
Blue Light ◽  
Nutritional Quality ◽  
Uv Light ◽  
Ultra Violet ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Daily Light Integral ◽  
Lettuce Growth ◽  
Supplemental Lighting

Blue light and ultra-violet (UV) light have been shown to influence plant growth, morphology, and quality. In this study, we investigated the effects of pre-harvest supplemental lighting using UV-A and blue (UV-A/Blue) light and red and blue (RB) light on growth and nutritional quality of lettuce grown hydroponically in two greenhouse experiments. The RB spectrum was applied pre-harvest for two days or nights, while the UV-A/Blue spectrum was applied pre-harvest for two or four days or nights. All pre-harvest supplemental lighting treatments had a same duration of 12 h with a photon flux density (PFD) of 171 μmol m−2 s−1. Results of both experiments showed that pre-harvest supplemental lighting using UV A/Blue or RB light can increase the growth and nutritional quality of lettuce grown hydroponically. The enhancement of lettuce growth and nutritional quality by the pre-harvest supplemental lighting was more effective under low daily light integral (DLI) compared to a high DLI and tended to be more effective when applied during the night, regardless of spectrum.

Study on the Visual Response of Frankliniella occidentalis to Ultra Violet-Visible Spectroscopy with Different Wavelength Ranges

2021 ◽  
Vol 15 (4) ◽  
pp. 497-503
Author(s):  
Qihang Liu ◽  
Yueli Jiang ◽  
Mingqian Zhao ◽  
Jin Miao ◽  
Zhongjun Gong ◽  
...  
Keyword(s):  
White Light ◽  
Frankliniella Occidentalis ◽  
Uv Light ◽  
Ultra Violet ◽  
Western Flower Thrips ◽  
Selection Response ◽  
Visual Sensitivity ◽  
Light Energy ◽  
Visual Response ◽  
Response Effect

To understand the visual sensitivity of western flower thrips to 350–450 nm light, we examined thrips selective response effect and the effect of white light on thrips visual response effect. The results showed that the visual selection response to Ultra Violet (UV) light at 360–365 nm, the approach sensitivity to 380–385 nm light with 6000 lx was respectively the best (15.59, 7.26%), while under light energy, both of them to 360–365 nm light with 60 mW/cm2 were the best (20.04, 11.13%). Under contrast white light, the most sensitive UV spectra of thrips respectively caused by illumination, light energy was 380–385, 360–365 nm, and white light enhanced thrips visual response effect to UV light, which further increased by the increasing intensity, showing that under illumination, the visual response effect to 380–385 nm light with 6000 lx was the best (51.21,69.78%), while that to 360–365 nm light with 60 mW/cm2 were the best (43.98, 65.68%), originated from the different intensity spread by light energy and illumination. These results indicate that the change of photo-stimulus intensity property can regulated thrips visual sensitivity to enhance the phototactic effect.

Observations of TiO2 Surfaces Using Totally Reflected X-ray In-plane Diffraction Under UV Irradiation

2002 ◽  
Vol 751 ◽  
Author(s):  
T. Horiuchi ◽  
H. Ochi ◽  
K. Kaisei ◽  
K. Ishida ◽  
K. Matsushige
Keyword(s):  
Uv Irradiation ◽  
Uv Light ◽  
Plane Surface ◽  
Signal To Noise Ratio ◽  
High Surface ◽  
Ultra Violet ◽  
High Signal ◽  
X Ray ◽  
Force Microscopy ◽  
Catalytic Activities

ABSTRACTSurface lattice displacements of titanium dioxide (TiO2: rutile) during ultra-violet (UV) light irradiation have been investigated using a total reflection x-ray diffraction, which provides a high signal to noise ratio (S/N) and superior in-plane surface diffraction. Under the environments in vapors of H2O, CH3OH, C2H5OH and C3H6OH, the photo-catalytic activities of TiO2 (110), (100) and (001) surfaces subject to UV irradiation have been measured. It is found that the diffraction peaks and their full width half maxima (FWHMs) show some peculiarities with respect to the photo-catalytic activities in both surface lattices and adsorbed molecules in vapors. Furthermore, Kelvin force microscopy (KFM) has showed that there exists a very high surface potential, probably due to surface atom displacements induced by UV irradiation. With regard to the origin of the photo-catalytic activities, the induced surface potentials are discussed.

scholarly journals DAYA PATOGENESITAS Helicoverpa armigera Nuclear Polyhedrosis Virus HaNPV SETELAH TERKENA RADIASI SINAR ULTRAVIOLET

2000 ◽  
Vol 6 (1) ◽  
pp. 65-70
Author(s):  
Mahanani Tri Asri ◽  
Isnawati Isnawati
Keyword(s):  
Biological Control ◽  
Helicoverpa Armigera ◽  
Nuclear Polyhedrosis Virus ◽  
Uv Light ◽  
Ultra Violet ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Helicoverpa Armígera ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis

This research is about pathogen capacity of the Helicoverpa armigera nuclear Polyhedrosis Virus (HaNPV) after irradiation by ultra violet (UV) light. The HaNPV is the one kind of the virus which attack the insect Helicoverpa armigera-attacker the some species of the crop life tobacco, cotton, potato, tomato. Because of that the HaNPV can be used as the biological control of the pest. Some researcher stated that the pathogen capacity of the HaNPV is decrease if the virus was expose in the ultra violet (UV) light. Because of the fact the virus in not useful as the biological control of the pest in the land corp. This research to test the statement. Laboratory experimental was done to tested the pathogen capacity of the HaNPV after irradiation treatment by the ultra violet light. The intensity of the UV light in this experiment were 28.7 lux, 97.3 lux, and 127.4 lux with the lighting period were 0, 1, 3, 6, 9, 12, and 15. The result of the research stated that the pathogen capacity of the HaNPV was not influenced by ultra violet light. So the virus is still useful as the biological control of the pest in the land crop.

Morphologic, Photocatalytic and Antibacterial Properties of ZnO-TiO2 Sol-Gel System

2018 ◽  
Vol 762 ◽  
pp. 278-282
Author(s):  
Anzelms Zukuls ◽  
Gundars Mežinskis ◽  
Aigars Reinis ◽  
Ingus Skadins ◽  
Juta Kroica ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Sol Gel ◽  
Antibacterial Properties ◽  
Ultra Violet ◽  
Properties Of Coatings ◽  
Force Microscopy ◽  
Glass Slides ◽  
Heat Treated ◽  
Colour Changes

Prepared and heat-treated sol-gel ZnO-TiO2 coatings onto microscope glass slides were characterised by atomic force microscopy (AFM), scanning electron microscopy (SEM), as well as absorption spectra of light has been obtained. Thermally treated xerogels were characterised by X-ray diffraction (XRD). As well as their photocatalytic activity using methyl orange (MO) and observing the colour changes over the time in visible light (VIS) and ultra violet (UV) light has been determined. The influence of ZnO concentration on morphology, photocatalytic activity and antibacterial properties of coatings was analysed. The growth of S. epidermidis on the surface of the samples was inhibited due to photocatalytic properties of coatings.

scholarly journals High-level expression of ice nuclei in a Pseudomonas syringae strain is induced by nutrient limitation and low temperature.

1993 ◽  
Vol 175 (13) ◽  
pp. 4062-4070 ◽  
Author(s):  
M Nemecek-Marshall ◽  
R LaDuca ◽  
R Fall
Keyword(s):  
Low Temperature ◽  
Nutrient Limitation ◽  
Pseudomonas Syringae ◽  
High Level Expression ◽  
Ice Nuclei ◽  
High Level
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