Tertiary DNA structure in the single-stranded hTERT promoter fragment unfolds and refolds by parallel pathways via cooperative or sequential events.
Tertiary DNA structure in the single-stranded hTERT promoter fragment unfolds and refolds by parallel pathways via cooperative or sequential events.
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DOI：
10.1021/ja210399h
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发表时间：
2012-03-21
影响因子：
15
通讯作者：
Mao, Hanbin
中科院分区：
文献类型：
--
作者：
Yu, Zhongbo;Gaerig, Vanessa;Cui, Yunxi;Kang, HyunJin;Gokhale, Vijay;Zhao, Yuan;Hurley, Laurence H.;Mao, Hanbin
The discovery of G-quadruplexes and other DNA secondary elements has increased the structural diversity of DNA well beyond the ubiquitous double helix. However, it remains to be determined whether tertiary interactions can take place in a DNA complex that contains more than one secondary structure. Using a new data analysis strategy that exploits the hysteresis region between the mechanical unfolding and refolding traces obtained by a laser-tweezers instrument, we now provide the first convincing kinetic and thermodynamic evidence that a higher order interaction takes place between a hairpin and a G-quadruplex in a single-stranded DNA fragment that is found in the promoter region of human telomerase. During the hierarchical unfolding or refolding of the DNA complex, a 15-nucleotide hairpin serves as a common species among three intermediates. Moreover, either a mutant that prevents this hairpin formation or the addition of a DNA fragment complementary to the hairpin destroys the cooperative kinetic events by removing the tertiary interaction mediated by the hairpin. The coexistence of the sequential and the cooperative refolding events provides direct evidence for a unifying kinetic partition mechanism previously observed only in large proteins and complex RNA structures. Not only does this result rationalize the current controversial observations for the long-range interaction in complex single-stranded DNA structures, but this unexpected complexity in a promoter element provides additional justification for the biological function of these structures in cells.
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影响因子：
5.6
作者：
Mills, JB;Vacano, E;Hagerman, PJ
通讯作者：
Hagerman, PJ
DOI：
10.1073/pnas.0508584102
发表时间：
2005-11-29
影响因子：
11.1
作者：
Laurence, TA;Kong, XX;Weiss, S
通讯作者：
Weiss, S
影响因子：
56.9
作者：
Onoa, B;Dumont, S;Bustamante, C
通讯作者：
Bustamante, C
DOI：
10.1073/pnas.0404549101
发表时间：
2004-11-16
影响因子：
11.1
作者：
Dietz, H;Rief, M
通讯作者：
Rief, M
DOI：
10.1002/prot.340220411
发表时间：
1995-08-01
期刊：
PROTEINS-STRUCTURE FUNCTION AND GENETICS
影响因子：
--
作者：
GOVINDARAJAN, S;GOLDSTEIN, RA
通讯作者：
GOLDSTEIN, RA