In 1990, Bai et al.first directly observed an unusual triple-stranded braid-likeconformation of denatured λ-DNA Hind Ⅲ in vitro with scanning tunneling microscopy(STM). The triple-stranded braid-like conformation pr...In 1990, Bai et al.first directly observed an unusual triple-stranded braid-likeconformation of denatured λ-DNA Hind Ⅲ in vitro with scanning tunneling microscopy(STM). The triple-stranded braid-like conformation presented in this work was dif-ferent from the model of the right-handed triple helix DNA proposed by otherauthors.In the triple helix model, the third strand winds round the major groove ofthe double helix DNA. Several studies indicated that the triple-stranded DNA, whichwas prepared by the reaction of homopurine and homopyrimidine or single-strandedDNA and doube-stranded DNA, had a low melting temperatue (T_m), a highabsorbance at 280 run in the unwinding process and was resistant to DNase展开更多
基金National Basic Research Program of China(2011CB707601)Natural Science Foundation of China(50875047,50925519,51005048,51003015)Jiangsu Province Nature Science Foundation(BK2008201,BK2009292)
文摘In 1990, Bai et al.first directly observed an unusual triple-stranded braid-likeconformation of denatured λ-DNA Hind Ⅲ in vitro with scanning tunneling microscopy(STM). The triple-stranded braid-like conformation presented in this work was dif-ferent from the model of the right-handed triple helix DNA proposed by otherauthors.In the triple helix model, the third strand winds round the major groove ofthe double helix DNA. Several studies indicated that the triple-stranded DNA, whichwas prepared by the reaction of homopurine and homopyrimidine or single-strandedDNA and doube-stranded DNA, had a low melting temperatue (T_m), a highabsorbance at 280 run in the unwinding process and was resistant to DNase
