Metal ion dependence of cooperative collapse transitions in RNA.
Metal ion dependence of cooperative collapse transitions in RNA.
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DOI：
10.1016/j.jmb.2009.08.044
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发表时间：
2009-10-30
影响因子：
5.6
通讯作者：
Woodson, Sarah A.
中科院分区：
文献类型：
--
作者：
Moghaddam, Sarvin;Caliskan, Gokhan;Chauhan, Seema;Hyeon, Changbong;Briber, R. M.;Thirumalai, D.;Woodson, Sarah A.
带正电荷的抗衡离子驱动RNA分子进入紧凑的构型，从而形成其生物活性结构。为了了解阳离子的价态和大小如何影响RNA中的塌缩转变，使用小角X射线散射来跟踪不同阳离子中Azoarcus和Tetrahymena核酶的回转半径（Rg）的减小。小，多价阳离子诱导的崩溃的两个核酶比单价离子更有效。因此，塌缩跃迁的协同性依赖于反电荷密度。奇异值分解的散射曲线表明，折叠的较小和更耐热的Azoarcus核酶是很好地描述了两个组件，而崩溃的较大的四膜虫核酶涉及至少一个中间体。从散射矢量的距离分布中提取的依赖于离子的持续长度表明，Azoarcus核酶在低电荷密度离子中的过渡中点处的灵活性低于高电荷密度离子。我们的结论是，在Azoarcus核酶的序列特异性三级相互作用的形成与磷酸盐电荷的中和重叠，而三级折叠的四膜虫核酶需要额外的抗衡离子。因此，RNA结构的稳定性决定了其对反离子的价态和大小的敏感性。
Positively charged counterions drive RNA molecules into compact configurations that lead to their biologically active structures. To understand how the valence and size of the cations influences the collapse transition in RNA, small angle X-ray scattering was used to follow the decrease in the radius of gyration (Rg) of the Azoarcus and Tetrahymena ribozymes in different cations. Small, multivalent cations induced the collapse of both ribozymes more efficiently than monovalent ions. Thus, the cooperativity of the collapse transition depends on the counterion charge density. Singular value decomposition of the scattering curves showed that folding of the smaller and more thermostable Azoarcus ribozyme is well described by two components, whereas collapse of the larger Tetrahymena ribozyme involves at least one intermediate. The ion-dependent persistence length, extracted from the distance distribution of the scattering vectors, shows that the Azoarcus ribozyme is less flexible at the midpoint of transition in low charge density ions than in high charge density ions. We conclude that the formation of sequence-specific tertiary interactions in the Azoarcus ribozyme overlaps with neutralization of the phosphate charge, while tertiary folding of the Tetrahymena ribozyme requires additional counterions. Thus, the stability of the RNA structure determines its sensitivity to the valence and size of the counterions.
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影响因子：
5.6
作者：
Heilman-Miller, SL;Thirumalai, D;Woodson, SA
通讯作者：
Woodson, SA
影响因子：
15
作者：
Koculi, Eda;Hyeon, Changbong;Woodson, Sarah A.
通讯作者：
Woodson, Sarah A.
影响因子：
5.6
作者：
Chauhan, Seema;Behrouzi, Reza;Woodson, Sarah A.
通讯作者：
Woodson, Sarah A.
DOI：
10.1038/nsb0797-553
发表时间：
1997-07-01
期刊：
NATURE STRUCTURAL BIOLOGY
影响因子：
--
作者：
Cate, JH;Hanna, RL;Doudna, JA
通讯作者：
Doudna, JA
影响因子：
56.9
作者：
Liphardt, J;Onoa, B;Bustamante, C
通讯作者：
Bustamante, C