Early melting of supercoiled DNA topoisomers observed by TGGE
نویسندگان
چکیده
منابع مشابه
Early melting of supercoiled DNA.
Denaturing gradient gel electrophoresis (formamide with urea) has been used to study the melting of supercoiled DNA. A linear gradient of denaturant concentration proportional to a 25 degrees C linear increase of temperature (Teff) from the left to the right edge of the gel was created perpendicular to DNA migration. The mobility of supercoiled DNA molecules was shown to drop to the level of re...
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The mechanism by which the type 2 topoisomerase from bacteriophage T4 mediates knotting of negatively supercoiled DNA was deduced from an analysis of product topology. The knotted products were nicked and then subjected to electrophoresis in order to separate species on the basis of the minimum number of crossings in the knotted form. Knots with defined numbers of crossings were purified and th...
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We study DNA supercoiling in a quantitative fashion by micromanipulating single linear DNA molecules with a magnetic field gradient. By anchoring one end of the DNA to multiple sites on a magnetic bead and the other end to multiple sites on a glass surface, we were able to exert torsional control on the DNA. A rotating magnetic field was used to induce rotation of the magnetic bead, and reversi...
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Supercoiling is introduced into DNAmolecules when the double helix is twisted around its own axis in three-dimensional space. Generally, DNAmolecules are negatively supercoiled inside cells, although the level of supercoiling is not equal throughout the genome and many supercoils may be constrained by bound proteins. Supercoiling increases the free energy of DNA and influences DNA metabolism by...
متن کاملDimensions of plectonemically supercoiled DNA.
With a view to determine the configuration and regularity of plectonemically supercoiled DNA, we have measured the small angle neutron scattering from pUC18 plasmid in saline solutions. Furthermore, we have derived the mathematical expression for the single chain scattering function (form factor) of a superhelical structure, including the longitudinal and transverse interference over the plecto...
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ژورنال
عنوان ژورنال: Nucleic Acids Research
سال: 2000
ISSN: 1362-4962
DOI: 10.1093/nar/28.11.e51