TY - JOUR
T1 - Non-complementary DNA helical structure induced by positive torsional stress
AU - Vologodskii, Alexander V.
AU - Yang, Xiaoping
AU - Seeman, Nadrian C.
N1 - Funding Information:
This research has been supported by grants GM-54215 (A.V.V.) and GM-29554 (N.C.S.) from the National Institute of General Medical Sciences, N000149810093 from the Office of Naval Research (N.C.S.), NSF-CCR-97-25021 from the National Science Foundation (N.C.S.) and by a Margaret and Herman Sokol Fellowship (X.Y.). We are grateful to Dr J.B.Chaires for valuable discussions about this work.
PY - 1998/3/15
Y1 - 1998/3/15
N2 - We have induced a local conformational transition by positive torsional stress in small synthetic circular DNA molecules containing cruciforms with immobile or tetramobile branched junctions. The immobile species correspond to the extruded and intruded extrema of the tetramobile junction. Under normal conditions the sequences of all the branched species prevent them from being re-absorbed into the circle. We have induced positive stress by addition of ethidium to the circle, in a low ionic strength medium. Alterations in gel electrophoretic mobility under increasing concentrations of ethidium suggest that the cruciforms undergo a transition under torsional stress. The product of this transition contains mispaired nucleotides, but interwound backbones. By comparing the electrophoretic mobilities of circles containing these structures with that of a completely complementary circle of the same length, we conclude that the twist in the mispairing region is similiar to that of completely paired species.
AB - We have induced a local conformational transition by positive torsional stress in small synthetic circular DNA molecules containing cruciforms with immobile or tetramobile branched junctions. The immobile species correspond to the extruded and intruded extrema of the tetramobile junction. Under normal conditions the sequences of all the branched species prevent them from being re-absorbed into the circle. We have induced positive stress by addition of ethidium to the circle, in a low ionic strength medium. Alterations in gel electrophoretic mobility under increasing concentrations of ethidium suggest that the cruciforms undergo a transition under torsional stress. The product of this transition contains mispaired nucleotides, but interwound backbones. By comparing the electrophoretic mobilities of circles containing these structures with that of a completely complementary circle of the same length, we conclude that the twist in the mispairing region is similiar to that of completely paired species.
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U2 - 10.1093/nar/26.6.1503
DO - 10.1093/nar/26.6.1503
M3 - Article
C2 - 9490798
AN - SCOPUS:0032520636
SN - 0305-1048
VL - 26
SP - 1503
EP - 1508
JO - Nucleic acids research
JF - Nucleic acids research
IS - 6
ER -