Structure of the human telomere in K+ solution: a stable basket-type G-quadruplex with only two G-tetrad layers.
Structure of the human telomere in K+ solution: a stable basket-type G-quadruplex with only two G-tetrad layers.
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DOI：
10.1021/ja807503g
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发表时间：
2009-04-01
影响因子：
15
通讯作者：
Phan AT
中科院分区：
文献类型：
--
作者：
Lim KW;Amrane S;Bouaziz S;Xu W;Mu Y;Patel DJ;Luu KN;Phan AT
以前，已经报道了人端粒DNA序列在不同的实验条件下可以采用四种不同的分子内G-四链体，每种分子内G-四链体包括三个G-四联体层，即Na+-溶液反平行链篮形式、K+-晶体平行链螺旋桨形式、K+-溶液（3+1）形式1和K+-溶液（3+1）形式2。在这里，我们提出了一个新的分子内G-四链体通过四个重复的人端粒序列在K+溶液（形式3）。这种结构是一个只有两层G-四联体的篮型G-四链体：环依次为边向、对角和边向;每个四联体周围的鸟嘌呤糖苷构象为syn·syn·anti·anti;核心的每条链都有平行和反平行的相邻链;有一个窄槽、一个宽槽和两个中等槽。尽管在核心中仅存在两个G-四联体，但这种结构比先前在K+溶液中观察到的人类端粒序列的三个G-四联体分子内G-四联体更稳定。形式3的详细结构解析揭示了覆盖G-四联体核心两端的环中的广泛碱基配对和堆叠，这可以解释结构的高稳定性。这种新的结构突出了人类端粒DNA的构象异质性。它揭示了G-四链体的新折叠原理，并提出了新的环序列和结构，用于靶向人类端粒DNA。
Previously, it has been reported that human telomeric DNA sequences could adopt in different experimental conditions four different intramolecular G-quadruplexes each involving three G-tetrad layers, namely Na+-solution antiparallel-stranded basket form, K+-crystal parallel-stranded propeller form, K+-solution (3+1) Form 1 and K+-solution (3+1) Form 2. Here we present a new intramolecular G-quadruplex adopted by a four-repeat human telomeric sequence in K+ solution (Form 3). This structure is a basket-type G-quadruplex with only two G-tetrad layers: loops are successively edgewise, diagonal and edgewise; glycosidic conformations of guanines are syn•syn•anti•anti around each tetrad; each strand of the core has both a parallel and an antiparallel adjacent strands; there are one narrow, one wide and two medium grooves. Despite the presence of only two G-tetrads in the core, this structure is more stable than the three-G-tetrad intramolecular G-quadruplexes previously observed for human telomeric sequences in K+ solution. Detailed structural elucidation of Form 3 revealed extensive base pairing and stacking in the loops capping both ends of the G-tetrad core, which might explain the high stability of the structure. This novel structure highlights the conformational heterogeneity of human telomeric DNA. It revealed a new folding principle for G-quadruplexes and suggests new loop sequences and structures for targeting in human telomeric DNA.
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影响因子：
5.6
作者：
Kuryavyi, V;Kettani, A;Patel, DJ
通讯作者：
Patel, DJ
影响因子：
14.9
作者：
He, YJ;Neumann, RD;Panyutin, IG
通讯作者：
Panyutin, IG
影响因子：
14.9
作者：
Ambrus A;Chen D;Dai J;Bialis T;Jones RA;Yang D
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Yang D
DOI：
10.1073/pnas.0506144102
发表时间：
2005-12-27
影响因子：
11.1
作者：
Lee, JY;Okumus, B;Ha, TJ
通讯作者：
Ha, TJ
影响因子：
2.7
作者：
D'Isa, G;Galeone, A;Mayol, L
通讯作者：
Mayol, L