Search results for "DNA-Directed RNA Polymerases"
showing 10 items of 30 documents
Quantitative characterization of translational riboregulators using an in vitro transcription–translation system
2018
Riboregulators are short RNA sequences that, upon binding to a ligand, change their secondary structure and influence the expression rate of a downstream gene. They constitute an attractive alternative to transcription factors for building synthetic gene regulatory networks because they can be engineered de novo. However, riboregulators are generally designed in silico and tested in vivo, which provides little quantitative information about their performances, thus hindering the improvement of design algorithms. Here we show that a cell-free transcription-translation (TX-TL) system provides valuable information about the performances of in silico designed riboregulators. We first propose a …
Asymmetric cell division requires specific mechanisms for adjusting global transcription
2017
Most cells divide symmetrically into two approximately identical cells. There are many examples, however, of asymmetric cell division that can generate sibling cell size differences. Whereas physical asymmetric division mechanisms and cell fate consequences have been investigated, the specific problem caused by asymmetric division at the transcription level has not yet been addressed. In symmetrically dividing cells the nascent transcription rate increases in parallel to cell volume to compensate it by keeping the actualmRNA synthesis rate constant. This cannot apply to the yeast Saccharomyces cerevisiae, where this mechanism would provoke a neverending increasing mRNA synthesis rate in sma…
Electrochemical probe for the monitoring of DNA-protein interactions.
2010
Self-assembly of thiol-terminated oligonucleotides on gold substrates provides a convenient way for DNA-functionalized surfaces. Here we describe the development of an electrochemical assay for the detection of DNA-protein interactions based on the modification of the electrochemical response of methylene blue (MB) intercalated in the DNA strands. Using a functionalized electrode with double stranded DNA carrying T3 RNA polymerase binding sequence, we show a substantial attenuation of the current upon the DNA-protein interaction. Moreover, a Langmuir binding isotherm for T3 RNA polymerase (T3 Pol) gives a dissociation constant K(D) equal to 0.46+/-0.23 microM. Such value is 100 times lower …
Thoughts on What Chemists Can Contribute to Fighting SARS-CoV-2 - A Short Note on Hand Sanitizers, Drug Candidates and Outreach.
2020
Abstract The SARS‐CoV‐2 outbreak causing the respiratory disease COVID‐19 has left many chemists in academia without an obvious option to contribute to fighting the pandemic. Some of our recent experiences indicate that there are ways to overcome this dilemma. A three‐pronged approach is proposed.
Comparison of DNase, DNA-polymerase and RNA-polymerase activities present in the DNA-bindung proteins of normal human dermis, epidermis, horny layer …
1978
DNA-binding proteins (DBP) of normal human dermis, epidermis, horny layer and psoriatic scales represent a tissue-specific group of mostly nuclear nonhistone proteins. To analyse their function, the different DBP fractions were examined concerning the presence of DNase, DNA-polymerase and RNA-polymerase activities. DBP of normal epidermis and horny layer contain four different DNases. One DNase of both DBP fractions is active only at pH 5.0. Three DNases of epidermal DBP are active at a pH-range from 5.0--8.5, while the corresponding DNases of horny layer-DBP are most active at pH 7.4. Probably these DNases have changed their pH-optimum during keratinisation. DBP of psoriatic scales include…
An MLSA approach for the taxonomic update of the Splendidus clade, a lineage containing several fish and shellfish pathogenic Vibrio spp.
2016
A multilocus sequence analysis was undertaken in order to redefine the Splendidus clade of the genus Vibrio, a large group of species containing several pathogenic members that affect fish and shellfish, and are difficult to identify through both phenotypic and genotypic approaches. The study included analysis of partial sequences of recA, gyrB, mreB, rpoD and pyrH genes, as well as the 16S rRNA gene. Seventeen type strain species were included that were complemented with other reference strains and a collection of isolates tentatively identified as members of this clade, as well as a set of other Vibrio species. The clade was well defined and stable in all analyses, and was confirmed to co…
Description of Enterovibrio nigricans sp. nov., reclassification of Vibrio calviensis as Enterovibrio calviensis comb. nov. and emended description o…
2009
Eleven strains of halophilic, facultative anaerobes isolated from healthy and diseased Dentex dentex and Sparus aurata (bony fishes) cultured in Spanish Mediterranean fisheries have been studied by a polyphasic approach that included a wide phenotypic characterization, DNA-DNA hybridization and phylogenetic analysis using 16S rRNA, recA and rpoD gene sequences. All strains were phylogenetically related to Enterovibrio species and Vibrio calviensis. On the basis of sequence analysis and DNA-DNA hybridization data, eight of the strains were identified as Enterovibrio coralii. The remaining three strains formed a tight, independent clade in all sequence analyses and showed less than 70 % DNA-D…
Phylogenetic analysis of the genera Proteus, Morganella and Providencia by comparison of rpoB sequences of type and clinical strains suggests the cla…
2010
Phylogenetic analysis of partial rpoB gene sequences of type and clinical strains belonging to different 16S rRNA gene-fingerprinting ribogroups within 11 species of enterobacteria of the genera Proteus, Morganella and Providencia was performed and allowed the definition of rpoB clades, supported by high bootstrap values and confirmed by ≥2.5 % nucleotide divergence. None of the resulting clades included strains belonging to different species and the majority of the species were confirmed as discrete and homogeneous. However, more than one distinct rpoB clade could be defined among strains belonging to the species Proteus vulgaris (two clades), Providencia alcalifaciens (two clades) and Pro…
Polyphasic taxonomic characterization of Lactobacillus rossiae isolates from Belgian and Italian sourdoughs reveals intraspecific heterogeneity.
2009
Abstract (GTG) 5 -PCR fingerprinting and pheS sequence analysis of 18 Lactobacillus rossiae isolates, mainly originating from Belgian and Italian artisan sourdoughs, revealed intraspecies grouping as evidenced by the delineation of three and two subgroups, respectively. On the other hand, 16S rRNA and rpoA gene sequence analysis and DNA–DNA hybridizations supported the accommodation of all isolates in a single species. No correlation between genetic and phenotypic heterogeneity was observed. Collectively, these data do not warrant taxonomic division of L. rossiae . On the other hand, the considerable differences in intraspecies sequence variation of L. rossiae isolates displayed by the pheS…
Cloning and expression of a cDNA copy of the viral K28 killer toxin gene in yeast
1995
The killer toxin K28, secreted by certain killer strains of the yeast Saccharomyces cerevisiae is genetically encoded by a 1.9 kb double-stranded RNA, M-dsRNA (M28), that is present within the cell as a cytoplasmically inherited virus-like particle (VLP). For stable maintenance and replication, M28-VLPs depend on a second dsRNA virus (LA), which has been shown to encode the major capsid protein (cap) and a capsid-polymerase fusion protein (cap-pol) that provides the toxin-coding M-satellites with their transcription and replicase functions. K28 toxin-coding M28-VLPs were isolated, purified and used in vitro for the synthesis of the single-stranded M28 transcript, which was shown to be of pl…