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Analyzing and Building Nucleic Acid Structures with 3DNA
Published on: April 26, 2013
Association of double-stranded DNA fragments into multistranded DNA structures
C Gaillard1, M Flavin, A Woisard
1Institut Jacques Monod, 2 place Jussieu, 75251 Paris 05, France.
Biopolymers
|November 5, 1999
Summary
DNA fragments can form stable, low-mobility complexes on polypropylene surfaces. These complexes arise from either strand dissociation and reassociation or local DNA unwinding, suggesting interactions with hydrophobic molecules in vivo.
Area of Science:
- Molecular Biology
- Biophysics
Background:
- Double-stranded DNA with poly(CA).poly(TG) repeats forms low-mobility complexes recognized by HMG1 and HMG2 proteins.
- Complex formation is influenced by DNA interactions with polypropylene surfaces, potentially involving strand dissociation and misaligned reassociation.
Purpose of the Study:
- To investigate the mechanisms of low-mobility DNA complex formation on polypropylene surfaces.
- To explore the role of DNA sequence and surface interactions in complex stability and structure.
Main Methods:
- In vitro experiments using double-stranded DNA fragments with and without repetitive sequences.
- High ionic strength conditions to study DNA-polypropylene interactions.
- Ligation of hairpin loop oligonucleotides to prevent strand separation.
Main Results:
- At high ionic strength, DNA strongly binds to polypropylene, suggesting potential in vivo interactions with hydrophobic molecules.
- Low-mobility complexes form on the polypropylene surface, irrespective of repetitive sequences.
- Preventing strand separation via ligation does not inhibit low-mobility complex formation.
Conclusions:
- Two pathways for low-mobility complex formation exist: 1) strand dissociation/misaligned reassociation of repeats, and 2) local DNA unwinding on the polypropylene surface enabling inter-duplex interactions.
- DNA-surface interactions, particularly with hydrophobic molecules, play a crucial role in DNA complex formation.
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