The Quick and the Dead: A Guide to Fast Phasing of Small Ribozyme and Riboswitch Crystal Structures.
The Quick and the Dead: A Guide to Fast Phasing of Small Ribozyme and Riboswitch Crystal Structures.
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快速与死亡：小核酶和核糖开关晶体结构快速定相指南。
DOI：
10.1007/978-1-4939-6433-8_17
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Wedekind,JosephE
中科院分区：
文献类型：
--
作者：
Jenkins,JermaineL;Wedekind,JosephE
核酶和核开关是非蛋白质编码（nc）RNA分子通过采用复杂的三维折叠实现生物活性的例子。这些分子在近原子分辨率下的可视化可以增强我们对化学基团如何在空间上组织的理解，从而为功能提供新的见解。这种方法有其挑战，主要涉及样品结晶，然后应用经验的结构测定方法，通常包括x射线衍射数据的实验“相位”。高质量晶体的缺乏或低对称空间群是需要在正在进行的实验中快速评估相位电位以确保成功结果的因素。在这里，我们描述了作为单波长或多波长异常衍射（SAD或MAD）相位的前奏的异常信噪比评估过程。测试案例包括一种自溶的62聚RNA酶，称为发夹核酶，以及一种结合修饰鸟嘌呤代谢物preQ1的33聚核开关。晶体分别用六检铱（III）和三酸锇（III）衍生化。然后对每个数据集进行xprepandshelxprograms，以评估异常的信噪比，并定位重原子子结构。随后在shelxeorresolve中进行噪声滤波。所描述的方法适用于RNA x射线衍射数据的快速相位，并在计划和执行实验结构确定的潜力方面，将内部x射线的有效性与同步辐射源的有效性进行对比。
Ribozymes and riboswitches are examples of non-protein-coding (nc)RNA molecules that achieve biological activity by adopting complex three-dimensional folds. Visualization of such molecules at near-atomic resolution can enhance our understanding of how chemical groups are organized spatially, thereby providing novel insight into function. This approach has its challenges, which mainly entail sample crystallization followed by the application of empirical, structure-determination methods that often include experimental “phasing” of X-ray diffraction data. A paucity of high-quality crystals or a low symmetry space group are factors that demand rapid assessment of phasing potential during an ongoing experiment in order to assure a successful outcome. Here we describe the process of evaluating the anomalous signal-to-noise as a prelude to single wavelength or multiwavelength anomalous diffraction (SAD or MAD) phasing. Test cases include an autolytic 62-mer RNA enzyme known as the hairpin ribozyme, and a 33-mer riboswitch that binds the modified guanine metabolite preQ1. The crystals were derivatized with iridium (III) hexammine and osmium (III) pentaammine triflate, respectively. Each data set was then subjected to theXprepandShelxprograms to assess the anomalous signal-to-noise and to locate the heavy-atom substructure. Subsequent noise filtering was conducted inShelxeorResolve. The methods described are applicable to the rapid phasing of RNA X-ray diffraction data, and contrast the efficacy of in-house X-rays with those attainable from synchrotron-radiation sources in terms of the potential to plan for and execute an experimental structure determination.
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影响因子：
--
作者：
B. C. Wang
通讯作者：
B. C. Wang
小核酶的纯化、结晶和 X 射线衍射分析。
影响因子：
--
作者：
J. Wedekind;D. Mckay
通讯作者：
D. Mckay
影响因子：
5.7
作者：
Keel, Amanda Y.;Rambo, Robert P.;Kieft, Jeffrey S.
通讯作者：
Kieft, Jeffrey S.
DOI：
10.1073/pnas.0506662102
发表时间：
2005-09-20
影响因子：
11.1
作者：
Kazantsev, AV;Krivenko, AA;Pace, NR
通讯作者：
Pace, NR