Search results for "Base pair"
showing 10 items of 81 documents
Detection of a new 3-base pair insertion mutation in the protease gene of human immunodeficiency virus type 1 during highly active antiretroviral the…
2005
To investigate a new insertion mutation in the protease (PR) gene of human immunodeficiency virus type 1 (HIV-1) in a patient extensively pretreated with antiretroviral drugs, genotypic analyses of plasma-derived viruses were performed by sequencing segments of 1302 nucleotides in the pol gene of HIV-1. Despite optimal compliance to highly active antiretroviral therapy (HAART) the patient showed poor virological success. Nucleotide sequences of retrospective available plasma samples exhibited a previously unknown 3-bp insertion mutation, corresponding to a leucine, between codons 31 and 32 of the PR gene. This kind of mutation appears to be very rare and it does not seem to be associated wi…
Quantification of the Detrimental Effect of a Single Primer-Template Mismatch by Real-Time PCR Using the 16S rRNA Gene as an Example
2008
ABSTRACT We investigated the effects of internal primer-template mismatches on the efficiency of PCR amplification using the 16S rRNA gene as the model template DNA. We observed that the presence of a single mismatch in the second half of the primer extension sequence can result in an underestimation of up to 1,000-fold of the gene copy number, depending on the primer and position of the mismatch.
Mitochondrial DNA Regionalism and Historical Demography in the Extant Populations of Chirocephalus kerkyrensis (Branchiopoda: Anostraca)
2012
BackgroundMediterranean temporary water bodies are important reservoirs of biodiversity and host a unique assemblage of diapausing aquatic invertebrates. These environments are currently vanishing because of increasing human pressure. Chirocephalus kerkyrensis is a fairy shrimp typical of temporary water bodies in Mediterranean plain forests and has undergone a substantial decline in number of populations in recent years due to habitat loss. We assessed patterns of genetic connectivity and phylogeographic history in the seven extant populations of the species from Albania, Corfu Is. (Greece), Southern and Central Italy.Methodology/principal findingsWe analyzed sequence variation at two mito…
A low repeat length in oligodendrocyte chromatin
1985
Abstract: The behavior of oligodendrocyte chromatin after micrococcal nuclease digestion of nuclei was assayed in brains of rats of four different ages. During oligodendrocyte differentiation, a decreasing sensitivity of the chromatin to enzymatic attack was observed. On the other hand, the nucleosomal repeat length showed a slight tendency to increase during development. It is worth noting that even the highest values reported here for “oligodendrocyte’ chromatin repeat lengths are significantly lower than 200 base pairs, the value previously reported by others for “non‐astrocytic glia.” Copyright © 1985, Wiley Blackwell. All rights reserved
DNA condensation with spermine dendrimers: interactions in solution, charge inversion, and morphology control
2011
In this report, we characterize the formation of structured condensates of 884 base pair, double stranded DNA and spin-labeled, second generation dendrons (SL-G2) that are spermine-based and cationic using continuous wave electron paramagnetic resonance spectroscopy (CW EPR) and transmission electron microscopy (TEM). The electrostatic interaction between DNA and SL-G2 in solution leads to condensation of DNA into densely packed structures. At a particular charge ratio of 2.3 (cationic charges/anionic charges), the structures appear as thick rod-like condensates of parallelly ordered, stretched DNA and SL-G2. Depending on the concentration of DNA, the charge ratio and the ionic strength, wh…
Usefulness of omp1 restriction mapping for avian Chlamydia psittaci isolate differentiation
1995
Abstract Sixty-five avian Chlamydia psittaci isolates collected worldwide, including 27 previously characterized reference strains, were analysed by restriction mapping of the major outer membrane protein gene ( omp1 ) obtained after DMA amplification by PCR. They were compared to 2 ruminant isolates, a feline pneumonitis and a guinea pig inclusion conjunctivitis (GPIC) isolate. According to their omp1 restriction patterns, avian strains were heterogeneous in that they exhibited 6 and 4 distinct patterns using Alu I and Mbo II restriction enzymes, respectively, thus defining 7 groups. However, 84% of the studied strains belonged to groups 1 to 4, which share a specific fragment triplet of 4…
The selective synthesis of metallanucleosides and metallanucleotides: a new tool for the functionalization of nucleic acids.
2012
Nucleobases team up: the efficient and selective preparation of purine-derived metallanucleosides, metallanucleotides, and metalladinucleotides having M-C bonds (M=Ir(III), Rh(III)) is reported for the first time. The results presented may be applied to the synthesis of functionalized nucleic acids, or DNA/RNA-modified segments.
Toward the development of metal-based synthetic nucleases: DNA binding and oxidative DNA cleavage of a mixed copper(II) complex with N-(9H-purin-6-yl…
2009
Abstract The complex [Cu(N9-ABS)(phen) 2 ]·3.6H 2 O, H 2 N9-ABS = N -(9 H -purin-6-yl)benzenesulfonamide and phen = 1,10-phenanthroline, has been synthesized and then characterized with the aid of X-ray diffraction, analytical, and spectroscopic techniques. The geometry of Cu(II) is distorted square pyramidal with the equatorial positions occupied by three N atoms from two phenantroline molecules and one N atom from the adenine ring of the sulfonamide ligand. The interaction of the complex with DNA was studied by means of viscosity measurements and fluorescence spectroscopy. The results pointed to a classic intercalation of the complex between the DNA base pairs. The complex was found to b…
Docking of indolo- and pyrrolo-pyrimidines to DNA. New DNA-interactive polycycles from amino-indoles/pyrroles and BMMA
2004
New indolo- and pyrrolo-pyrimidines of type 1-4 were studied for their ability to form stable complexes with DNA fragments. The calculated free energies of binding were found in the range -8.39 ÷ -16.72 Kcal/mol. The docking studies revealed a common binding mode with the chromophore intercalated between GC base pairs whereas the side chain lies along the minor groove.
Dissipative lattice model with exact traveling discrete kink-soliton solutions: Discrete breather generation and reaction diffusion regime
1999
International audience; We introduce a nonlinear Klein-Gordon lattice model with specific double-well on-site potential, additional constant external force and dissipation terms, which admits exact discrete kink or traveling wave fronts solutions. In the nondissipative or conservative regime, our numerical simulations show that narrow kinks can propagate freely, and reveal that static or moving discrete breathers, with a finite but long lifetime, can emerge from kink-antikink collisions. In the general dissipative regime, the lifetime of these breathers depends on the importance of the dissipative effects. In the overdamped or diffusive regime, the general equation of motion reduces to a di…