3-[(2-Hydroxybenzyl)azaniumyl]propanoate monohydrate

The title compound, C10H13NO3·H2O, is a zwitterion hydrate with the zwitterion comprising a central ammonium group and a carboxyl­ate residue. In the zwitterion, the hy­droxy­benzene and carboxyl­ate groups are directed to the same side of the mol­ecule and each orientated to place an O atom in a position to form an intra­molecular ammonium-N-H...O hydrogen bond, each closing an S(6) loop. The three-dimensional architecture is stabilized by hy­droxy-O-H...O(carboxyl­ate), water-O-H...O(carboxyl­ate) and ammonium-N-H...O(water) hydrogen bonds

Polymerase manager protein UmuD directly regulates Escherichia coli DNA polymerase III α binding to ssDNA

Replication by Escherichia coli DNA polymerase III is disrupted on encountering DNA damage. Consequently, specialized Y-family DNA polymerases are used to bypass DNA damage. The protein UmuD is extensively involved in modulating cellular responses to DNA damage and may play a role in DNA polymerase exchange for damage tolerance. In the absence of DNA, UmuD interacts with the α subunit of DNA polymerase III at two distinct binding sites, one of which is adjacent to the single-stranded DNA-binding site of α. Here, we use single molecule DNA stretching experiments to demonstrate that UmuD specifically inhibits binding of α to ssDNA. We predict using molecular modeling that UmuD residues D91 and G92 are involved in this interaction and demonstrate that mutation of these residues disrupts the interaction. Our results suggest that competition between UmuD and ssDNA for α binding is a new mechanism for polymerase exchange

Wireless Power Transmission

Wireless Power Transmission through inductive coupling is one of the new emerging technologies that will bring tremendous change in human life. Due to shortage of time and fast running life style it is difficult to carry the complete charging set which increases the demand of the wirelessly charged products. Wireless power transfer is one of the simplest and inexpensive ways of charging as it eliminate the use of conventional copper cables and current carrying wires. In this paper, a technique is devised for a wireless power transfer through induction, and a feasible design is modeled accordingly. The technique used in this paper is the inductive coupling as it the easiest method of high efficiency power transfer without using wired medium (eg, transformer). In this paper the result of experiment is given which is done to check wireless working of a simple application by glowing LED, and charging a mobile. Wireless power transfer is not much affected by placing hurdles likes books, hands and plastic between transceiver and receiver. This research work focuses on the study of wireless power transfer for the purpose of transferring cut and dried amount of energy at maximum efficiency

Rad51 Paralogs Remodel Pre-synaptic Rad51 Filaments to Stimulate Homologous Recombination

SummaryRepair of DNA double strand breaks by homologous recombination (HR) is initiated by Rad51 filament nucleation on single-stranded DNA (ssDNA), which catalyzes strand exchange with homologous duplex DNA. BRCA2 and the Rad51 paralogs are tumor suppressors and critical mediators of Rad51. To gain insight into Rad51 paralog function, we investigated a heterodimeric Rad51 paralog complex, RFS-1/RIP-1, and uncovered the molecular basis by which Rad51 paralogs promote HR. Unlike BRCA2, which nucleates RAD-51-ssDNA filaments, RFS-1/RIP-1 binds and remodels pre-synaptic filaments to a stabilized, “open,” and flexible conformation, in which the ssDNA is more accessible to nuclease digestion and RAD-51 dissociation rate is reduced. Walker box mutations in RFS-1, which abolish filament remodeling, fail to stimulate RAD-51 strand exchange activity, demonstrating that remodeling is essential for RFS-1/RIP-1 function. We propose that Rad51 paralogs stimulate HR by remodeling the Rad51 filament, priming it for strand exchange with the template duplex

A single zinc finger optimizes the DNA interactions of the nucleocapsid protein of the yeast retrotransposon Ty3

Reverse transcription in retroviruses and retrotransposons requires nucleic acid chaperones, which drive the rearrangement of nucleic acid conformation. The nucleic acid chaperone properties of the human immunodeficiency virus type-1 (HIV-1) nucleocapsid (NC) protein have been extensively studied, and nucleic acid aggregation, duplex destabilization and rapid binding kinetics have been identified as major components of its activity. However, the properties of other nucleic acid chaperone proteins, such as retrotransposon Ty3 NC, a likely ancestor of HIV-1 NC, are not well understood. In addition, it is unclear whether a single zinc finger is sufficient to optimize the properties characteristic of HIV-1 NC. We used single-molecule DNA stretching as a method for detailed characterization of Ty3 NC chaperone activity. We found that wild type Ty3 NC aggregates single- and double-stranded DNA, weakly stabilizes dsDNA, and exhibits rapid binding kinetics. Single-molecule studies in the presence of Ty3 NC mutants show that the N-terminal basic residues and the unique zinc finger at the C-terminus are required for optimum chaperone activity in this system. While the single zinc finger is capable of optimizing Ty3 NC's DNA interaction kinetics, two zinc fingers may be necessary in order to facilitate the DNA destabilization exhibited by HIV-1 NC

Bak Compensated for Bax in p53-null Cells to Release Cytochrome c for the Initiation of Mitochondrial Signaling during Withanolide D-Induced Apoptosis

The goal of cancer chemotherapy to induce multi-directional apoptosis as targeting a single pathway is unable to decrease all the downstream effect arises from crosstalk. Present study reports that Withanolide D (WithaD), a steroidal lactone isolated from Withania somnifera, induced cellular apoptosis in which mitochondria and p53 were intricately involved. In MOLT-3 and HCT116p53+/+ cells, WithaD induced crosstalk between intrinsic and extrinsic signaling through Bid, whereas in K562 and HCT116p53−/− cells, only intrinsic pathway was activated where Bid remain unaltered. WithaD showed pronounced activation of p53 in cancer cells. Moreover, lowered apoptogenic effect of HCT116p53−/− over HCT116p53+/+ established a strong correlation between WithaD-mediated apoptosis and p53. WithaD induced Bax and Bak upregulation in HCT116p53+/+, whereas increase only Bak expression in HCT116p53−/− cells, which was coordinated with augmented p53 expression. p53 inhibition substantially reduced Bax level and failed to inhibit Bak upregulation in HCT116p53+/+ cells confirming p53-dependent Bax and p53-independent Bak activation. Additionally, in HCT116p53+/+ cells, combined loss of Bax and Bak (HCT116Bax−Bak−) reduced WithaD-induced apoptosis and completely blocked cytochrome c release whereas single loss of Bax or Bak (HCT116Bax−Bak+/HCT116Bax+Bak−) was only marginally effective after WithaD treatment. In HCT116p53−/− cells, though Bax translocation to mitochondria was abrogated, Bak oligomerization helped the cells to release cytochrome c even before the disruption of mitochondrial membrane potential. WithaD also showed in vitro growth-inhibitory activity against an array of p53 wild type and null cancer cells and K562 xenograft in vivo. Taken together, WithaD elicited apoptosis in malignant cells through Bax/Bak dependent pathway in p53-wild type cells, whereas Bak compensated against loss of Bax in p53-null cells

Comment on: Comfort After Refitting Symptomatic Habitual Reusable Toric Lens Wearers with a New Daily Disposable Contact Lens for Astigmatism [Letter]

Suraj Kumar Chaurasiya,1,2 Mahendra Singh,1 Ritu Ray1 1Department of Optometry and Vision Science, CL Gupta Eye Institute, Moradabad, UP, 244001, India; 2Department of Contact Lens and Anterior Segment, CL Gupta Eye Institute, Moradabad, UP, 244001, IndiaCorrespondence: Suraj Kumar Chaurasiya, CL Gupta Eye Institute, Ram Ganga Vihar Phase II (Extn), Moradabad, UP, 244001, India, Tel +91-8809893186, Email [email protected]