scholarly journals Identification of a microsatellite region composed of a long homopurine/homopyrimidine tract surrounded by AT-rich sequences upstream of the rat stress-inducible hsp 70.1 gene.

1997 ◽  
Vol 44 (1) ◽  
pp. 147-152 ◽  
Author(s):  
K Lisowska ◽  
T Loch ◽  
A Fiszer-Kierzkowska ◽  
D Scieglińska ◽  
Z Krawczyk
Keyword(s):  
Inverted Repeat ◽  
Cleavage Site ◽  
Dna Structure ◽  
Transcription Unit ◽  
Hsp 70 ◽  
Microsatellite Sequence ◽  
Dna Molecule ◽  
Double Stranded Dna ◽  
Dna Fragment ◽  
Susceptibility Assay

A DNA region containing several repetitive motifs has been detected about 1.9 kbp upstream of the transcription unit of the rat stress-inducible hsp 70.1 gene. The most interesting element of this area is a microsatellite sequence (GA)6CAG(TC)24 that consists of an inverted repeat partially overlapping with the long homopurine/homopyrimidine tract (Pu/Py). DNA molecule within the described sequence can theoretically adopt alternate, non-B structures (H-DNA or cruciform) containing single-stranded regions. This microsatellite region is flanked by AT-rich sequences containing several poly(A) tracts. The longest of them with a possible potential to destabilized a double-stranded DNA helix is localized around 160 bp downstream the (GA)6CAG(TC)24. The DNA fragment containing sequences described above was subcloned into the pUC19 vector and the resulting plasmid was subjected to the standard S1 susceptibility assay. Preliminary mapping of the S1 cleavage site indicates for the formation of the non-B-DNA structure within the Pu/Py tract. This is to our knowledge a first report on the existence of a complex microsatellite region on upstream the 5'-end of the hsp 70 gene in mammals.

scholarly journals High-resolution mapping of heteroduplex DNA formed during UV-induced and spontaneous mitotic recombination events in yeast

2017 ◽  
Author(s):  
Yi Yin ◽  
Margaret Dominska ◽  
Eunice Yim ◽  
Thomas D. Petes
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Mitotic Recombination ◽  
Template Switching ◽  
Wild Type ◽  
Dna Breaks ◽  
Repair Synthesis ◽  
Heteroduplex Dna ◽  
Dna Molecule ◽  
Double Stranded Dna

AbstractDouble-stranded DNA breaks (DSBs) can be generated by both endogenous and exogenous agents. In diploid yeast strains, such breaks are usually repaired by homologous recombination (HR), and a number of different HR pathways have been described. An early step for all HR pathways is formation of a heteroduplex, in which a single-strand from the broken DNA molecule pairs with a strand derived from an intact DNA molecule. If the two strands of DNA are not identical, within the heteroduplex DNA (hetDNA), there will be mismatches. In a wild-type strain, these mismatches are removed by the mismatch repair (MMR) system. In strains lacking MMR, the mismatches persist and can be detected by a variety of genetic and physical techniques. Most previous studies involving hetDNA formed during mitotic recombination have been restricted to a single locus with DSBs induced at a defined position by a site-specific endonuclease. In addition, in most of these studies, recombination between repeated genes was examined; in such studies, the sequence homologies were usually less than 5 kb. In the present study, we present a global mapping of hetDNA formed in a UV-treated MMR-defective mlh1 strain. Although about two-thirds of the recombination events were associated with hetDNA with a continuous array of unrepaired mismatches, in about one-third of the events, we found regions of unrepaired mismatches flanking regions without mismatches. We suggest that these discontinuous hetDNAs involve template switching during repair synthesis, repair of a double-stranded DNA gap, and/or Mlh1-independent MMR. Many of our observed events are not explicable by the simplest form of the double-strand break repair (DSBR) model of recombination. We also studied hetDNA associated with spontaneous recombination events selected on chromosomes IV and V in a wild-type strain. The interval on chromosome IV contained a hotspot for spontaneous crossovers generated by an inverted pair of transposable elements (HS4). We showed that HS4-induced recombination events are associated with the formation of very large (>30 kb) double-stranded DNA gaps.

scholarly journals Footprinting studies on the effect of echinomycin on the structure of a bent DNA fragment

1990 ◽  
Vol 269 (1) ◽  
pp. 217-221 ◽  
Author(s):  
K R Fox ◽  
E Kentebe
Keyword(s):  
Binding Sites ◽  
Dna Structure ◽  
Drug Binding ◽  
Micrococcal Nuclease ◽  
Kinetoplast Dna ◽  
Bent Dna ◽  
Diethyl Pyrocarbonate ◽  
Drug Binding Sites ◽  
Dna Fragment

The interaction of echinomycin with a kinetoplast DNA fragment which contains phased runs of adenine residues has been examined by various footprinting techniques. DNAase I footprinting confirms that all drug-binding sites contain the dinucleotide CpG. However, not all such sequences are protected. Three sites, each of which is located between two adenine tracks in the sequence GCGA, are not protected from DNAase I attack. Enhanced cleavage by DNAase I, DNAase II and micrococcal nuclease is observed in regions surrounding drug-binding sites. The results suggest that echinomycin alters the conformation of the AT tracks, making them more like an average DNA structure. Echinomycin renders adenine residues in the sequence CGA hyper-reactive to diethyl pyrocarbonate.

scholarly journals Separation of Micronuclear DNA of Stylonychia lemnae by Pulsed-Field Electrophoresis and Identification of a DNA Molecule with a High Copy Number

1999 ◽  
Vol 9 (7) ◽  
pp. 654-661
Author(s):  
Christian Maercker ◽  
Heike Kortwig ◽  
Hans J. Lipps
Keyword(s):  
Copy Number ◽  
High Copy Number ◽  
Pulsed Field ◽  
Macronuclear Development ◽  
Dna Molecule ◽  
Pulsed Field Electrophoresis ◽  
Dna Fragment ◽  
Nuclear Differentiation ◽  
Excellent Tool ◽  
Very High

DNA from the hypotrichous ciliatae Stylonychia lemnae was separated by PFGE. In addition to the separation of the macronuclear DNA molecules with a size up to ∼40 kb, we were able to separate the micronuclear DNA with a size between ∼90 kb and 2 Mb. One very prominent 90-kb DNA band appeared on the pulsed-field gels. We propose that this 90-kb DNA fragment represents a linear plasmid residing in the micronucleus in a very high copy number. About 10% of the micronuclear DNA consists of the 90-kb DNA molecule. It appears in the micronucleus as well as in the macronuclear anlagen during macronuclear development but not in the mature macronucleus. Thus, the multicopy DNA is eliminated during fragmentation of the macronuclear anlagen DNA in the course of macronuclear development. Therefore, this 90-kb DNA molecule might serve as an excellent tool to study the recognition and elimination of DNA during nuclear differentiation of hypotrichous ciliates.

Exploration of Spin-Dependent Thermoelectricity in the Chiral Double-Stranded DNA Molecule Coupled to Ferromagnetic Leads

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Lei-Lei Nian ◽  
Long Bai ◽  
Wenting Yu ◽  
Jun Tang ◽  
Huichao Li ◽  
...  
Keyword(s):  
Dna Molecule ◽  
Double Stranded Dna

A Novel Unusual DNA Structure Formed in an Inverted Repeat Sequence

1998 ◽  
Vol 246 (2) ◽  
pp. 532-534 ◽  
Author(s):  
Mikio Kato ◽  
Kyouko Matsunaga ◽  
Nobuyoshi Shimizu
Keyword(s):  
Inverted Repeat ◽  
Dna Structure ◽  
Repeat Sequence ◽  
Inverted Repeat Sequence

scholarly journals Simulating Molecular Interactions of Carbon Nanoparticles with a Double-Stranded DNA Fragment

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Zhuang Wang ◽  
Hao Fang ◽  
Se Wang ◽  
Fan Zhang ◽  
Degao Wang
Keyword(s):  
Carbon Nanotube ◽  
Quantum Dot ◽  
Molecular Interactions ◽  
Carbon Nanoparticles ◽  
Large Scale ◽  
Electrostatic Force ◽  
Md Simulations ◽  
Single Walled Carbon Nanotube ◽  
Double Stranded Dna ◽  
Dna Fragment

Molecular interactions between carbon nanoparticles (CNPs) and a double-stranded deoxyribonucleic acid (dsDNA) fragment were investigated using molecular dynamics (MD) simulations. Six types of CNPs including fullerenes (C60and C70), (8,0) single-walled carbon nanotube (SWNT), (8,0) double-walled carbon nanotube (DWNT), graphene quantum dot (GQD), and graphene oxide quantum dot (GOQD) were studied. Analysis of the best geometry indicates that the dsDNA fragment can bind to CNPs through pi-stacking and T-shape. Moreover, C60, DWNT, and GOQD bind to the dsDNA molecules at the minor groove of the nucleotide, and C70, SWNT, and GQD bind to the dsDNA molecules at the hydrophobic ends. Estimated interaction energy implies that van der Waals force may mainly contribute to the mechanisms for the dsDNA-C60, dsDNA-C70, and dsDNA-SWNT interactions and electrostatic force may contribute considerably to the dsDNA-DWNT, dsDNA-GQD, and dsDNA-GOQD interactions. On the basis of the results from large-scale MD simulations, it was found that the presence of the dsDNA enhances the dispersion of C60, C70, and SWNT in water and has a slight impact on DWNT, GQD, and GOQD.

scholarly journals Crystal structure of the DNA sequence d(CGTGAATTCACG)2with DAPI

2017 ◽  
Vol 73 (9) ◽  
pp. 500-504 ◽  
Author(s):  
Hristina I. Sbirkova-Dimitrova ◽  
Boris Shivachev
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Minor Groove ◽  
Van Der Waals Interactions ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Base Pairs ◽  
X Ray ◽  
Dna Molecule ◽  
Dna Fragment

The structure of 4′,6-diamidine-2-phenylindole (DAPI) bound to the synthetic B-DNA oligonucleotide d(CGTGAATTCACG) has been solved in space groupP212121by single-crystal X-ray diffraction at a resolution of 2.2 Å. The structure is nearly isomorphous to that of the previously reported crystal structure of the oligonucleotide d(CGTGAATTCACG) alone. The adjustments in crystal packing between the native DNA molecule and the DNA–DAPI complex are described. DAPI lies in the narrow minor groove near the centre of the B-DNA fragment, positioned over the A–T base pairs. It is bound to the DNA by hydrogen-bonding and van der Waals interactions. Comparison of the two structures (with and without ligand) shows that DAPI inserts into the minor groove, displacing the ordered spine waters. Indeed, as DAPI is hydrophobic it confers this behaviour on the DNA and thus restricts the presence of water molecules.

Sign in / Sign up

Export Citation Format

Share Document