The Nonnatural Deoxyribonucleoside D3 Incorporated in an Intramolecular DNA Triplex Binds Sequence Specifically by Intercalation
The Nonnatural Deoxyribonucleoside D3 Incorporated in an Intramolecular DNA Triplex Binds Sequence Specifically by Intercalation
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掺入分子内 DNA 三链体的非天然脱氧核糖核苷 D3 通过插入特异性结合序列
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
J. Feigon
中科院分区：
文献类型：
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作者：
K. Koshlap;Paul Gillespie;P. Dervan;J. Feigon
寡核苷酸定向三螺旋结构是一种
Oligonucleotide-directed triple helix formation is one of the
most powerful methods for the sequence-specific recognition of
double-helical DNA. Pyrimidine oligonucleotides bind purine
tracts in the major groove of DNA parallel to the purine Watson-Crick
strand through the formation of specific Hoogsteen-type
hydrogen bonds. Specificity is derived from thymine (T)
recognition of adenine·thymine (A·T) base pairs (T·A·T triplet)
and N3-protonated cytosine (C+) recognition of guanine-cytosine
(G·C) base pairs (C + G·C triplets). The sequence-specific
recognition of double-helical DNA by a third strand to form a
triple helix is limited to mostly purine tracts. Although G in the
third strand has been found to specifically bind to T·A, the lower
stability of the G·T·A triplet and its dependence on the sequence
of the neigh boring triplets reveals that this will have limitations.
In an attempt to extend the recognition code to all four Watson-Crick
base pairs, the nonnatural deoxyribonucleoside 1-(2-deoxy/
β-D-ribofuranosyl)-4-(3-benzamido)phenylimidazole [D_3] was
synthesized and incorporated into pyrimidine DNA oligonucleotides
(Figure 1a). It was found that D_3 selectively recognizes
both T·A and C·G Watson-Crick base pairs within the
pyrimidine·purine·pyrimidine triple-helix motif. This was also
found to have a nearest neighbor dependence.