Search results for "Base"
showing 10 items of 8362 documents
Genomic structure and promoter analysis of pathogen-inducedrepatgenes fromSpodoptera exigua
2009
The repat gene family encodes midgut proteins overexpressed in response to pathogen infection in the lepidopteran Spodoptera exigua. Up-regulation of repat genes has been observed after challenging the larvae with both Bacillus thuringiensis toxins and after infection with the baculovirus Autographa californica multiple nucleopolyhedrovirus. In our study, PCR amplification of the genomic region and genome walking were used to obtain the genomic structure and the sequence of the 5'-upstream region of repat1 and repat2, two of the most phylogenetically distant members of the repat family. A similar gene structure between repat1 and repat2 has been found, with conserved exon-intron positions a…
Modulation of Hepatitis C Virus NS5A Hyperphosphorylation by Nonstructural Proteins NS3, NS4A, and NS4B
1999
NS5A of the hepatitis C virus (HCV) is a highly phosphorylated protein involved in resistance against interferon and required most likely for replication of the viral genome. Phosphorylation of this protein is mediated by a cellular kinase(s) generating multiple proteins with different electrophoretic mobilities. In the case of the genotype 1b isolate HCV-J, in addition to the basal phosphorylated NS5A (designated pp56), a hyperphosphorylated form (pp58) was found on coexpression of NS4A (T. Kaneko, Y. Tanji, S. Satoh, M. Hijikata, S. Asabe, K. Kimura, and K. Shimotohno, Biochem. Biophys. Res. Commun. 205:320‐326, 1994). Using a comparative analysis of two full-length genomes of genotype 1b…
Functional properties of a monoclonal antibody inhibiting the hepatitis C virus RNA-dependent RNA polymerase.
2001
The hepatitis C virus (HCV) RNA-dependent RNA polymerase (RdRp), represented by nonstructural protein 5B (NS5B), has recently emerged as a promising target for antiviral intervention. Here, we describe the isolation, functional characterization, and molecular cloning of a monoclonal antibody (mAb) inhibiting the HCV RdRp. This mAb, designated 5B-12B7, binds with high affinity to a conformational epitope in the palm subdomain of the HCV RdRp and recognizes native NS5B expressed in the context of the entire HCV polyprotein or subgenomic replicons. Complete inhibition of RdRp activity in vitro was observed at equimolar concentrations of NS5B and mAb 5B-12B7, whereas RdRp activities of classica…
The closest relatives of icosahedral viruses of thermophilic bacteria are among viruses and plasmids of the halophilic archaea.
2009
We have sequenced the genome and identified the structural proteins and lipids of the novel membranecontaining, icosahedral virus P23-77 of Thermus thermophilus. P23-77 has an 17-kb circular double-stranded DNA genome, which was annotated to contain 37 putative genes. Virions were subjected to dissociation analysis, and five protein species were shown to associate with the internal viral membrane, while three were constituents of the protein capsid. Analysis of the bacteriophage genome revealed it to be evolutionarily related to another Thermus phage (IN93), archaeal Halobacterium plasmid (pHH205), a genetic element integrated into Haloarcula genome (designated here as IHP for integrated Ha…
Biochemical properties of hepatitis C virus NS5B RNA-dependent RNA polymerase and identification of amino acid sequence motifs essential for enzymati…
1997
The NS5B protein of the hepatitis C virus (HCV) is an RNA-dependent RNA polymerase (RdRp) (S.-E. Behrens, L. Tomei, and R. De Francesco, EMBO J. 15:12-22, 1996) that is assumed to be required for replication of the viral genome. To further study the biochemical and structural properties of this enzyme, an NS5B-hexahistidine fusion protein was expressed with recombinant baculoviruses in insect cells and purified to near homogeneity. The enzyme was found to have a primer-dependent RdRp activity that was able to copy a complete in vitro-transcribed HCV genome in the absence of additional viral or cellular factors. Filter binding assays and competition experiments showed that the purified enzym…
In vitro studies on the activation of the hepatitis C virus NS3 proteinase by the NS4A cofactor.
1996
AbstractProteolytic processing of the nonstructural proteins of the hepatitis C virus (HCV) is mediated by two viral proteinases: the NS2-3 proteinase cleaving at the NS2/3 junction and the NS3 serine-type proteinase responsible for processing at the NS3/4A, NS4A/B, NS4B/5A, and NS5A/B sites. Activity of the NS3 proteinase is modulated by NS4A. In the absence of this cofactor processing at the NS3-dependent sites does not occur or, in the case of the NS5A/B junction, is poor but increased when NS4A is present. Although recent studies demonstrated that proteinase activation requires direct interaction between NS3 and NS4A, the mechanism by which NS4A exerts the activation function is not kno…
Molecular Characterization of a Variant of Bacillus anthracis-Specific Phage AP50 with Improved Bacteriolytic Activity▿ †
2008
ABSTRACT The genome sequence of a Bacillus anthracis -specific clear plaque mutant phage, AP50c, contains 31 open reading frames spanning 14,398 bp, has two mutations compared to wild-type AP50t, and has a colinear genome architecture highly similar to that of gram-positive Tectiviridae phages. Spontaneous AP50c-resistant B. anthracis mutants exhibit a mucoid colony phenotype.
Decoupled control scheme of grid-connected split-source inverters
2017
Grid-connected power conversion systems for renewable energy sources must fulfill several requirements, e.g., the high efficiency, the reduced cost and complexity, and, quite often, the boost capabilities that is usually achieved using a front-end dc–dc boost converter before the inversion stage, leading to a two-stage architecture. Meanwhile, single-stage power conversion systems, which perform the boosting operation within the inversion one, offer some potential advantages, in terms of reducing the complexity and the volume of the whole system. Among several proposed options, the split-source inverter (SSI) has been recently proposed by Abdelhakim et al. as an alternative option with some…
Electrochemical sensor for phosphate ions based on laser scriber reduced graphene oxide
2022
This preliminary work shows a new and innovative way to produce laser scribed reduced graphene oxide (LSGO) electrodes using different porous substrates (ranging from paper to plastic and fabric). The obtained electrodes were also tested as electrochemical sensors towards the detection of phosphate ions in water. To obtain the electrodes, a water suspension of GO was filtered on top of substrate (such as Whatman® filter paper) and a complete sensor was obtained from its reduction using a CO2 laser. The electrode is composed of working and counter electrodes made of LSGO and a reference electrode of a Ag/AgCl obtained by using a commercial AgCl conductive paste. Phosphate ions were detected …
El consumidor especialmente vulnerable: de la protección class-based a la protección state-based
2022
El presente estudio centra su atención en la regulación, desde un punto de vista sustantivo, de la figura del consumidor especialmente vulnerable y de su protección. El legislador español ha querido dar un paso adelante mediante la introducción de dicha figura en el Texto Refundido de la Ley General para la Defensa de los Consumidores y Usuarios (TRLGDCU). Así, la opción escogida ha sido la de incorporar un concepto dinámico del consumidor vulnerable (protección “state-based”), alejado de la concepción tradicional caracterizada por una perspectiva basada exclusivamente en las características individuales (protección “class-based”), que no consideraba factores externos relativos a la situaci…