supercoiled DNA


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supercoiled DNA

a conformation of a circular DNA molecule or a linear molecule, in which the ends of the DNA strands are not free to rotate, whereby the double helix is further twisted into a more compact structure. This puts extra tension into the molecule. Certain ENZYMES, such as topoisomerases and gyrases, can alter the amount of supercoiling of the DNA. The EXPRESSION of some GENES is influenced by the extent of supercoiling of the molecule
References in periodicals archive ?
Moreover, the low levels of supercoiled DNA observed could be because of the intensive binding with PBAE, resulting in change in their conformation.
Evodiamine exhibited Topo I inhibitory activities since the relaxation of supercoiled DNA was totally inhibited (Fig.
Based on such findings, the transformation efficiency was calculated using the mean of three replicates and was found to be 1.1 x [10.sup.6] transformants/[micro]g of transformed supercoiled DNA. The numbers of colonies using 50 and 100 [micro]l plating volumes were considered innumerable being much out the maximum limit of 300 colonies per plate.
Al at very low concentration unwinds the supercoiled DNA irreversibly (90).