CONFORMATIONAL ANALYSIS OF RIBOSWITCH APTAMERS BY SAXS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 本年度GUP-21939：本GUP是GUP11627(2008年)和GUP12457(2009年)的后续版本，在这两个版本中，我们研究了核糖开关与同源小分子结合时构象变化的一般特征。 核糖开关是基因调控的信使核糖核酸结构域，通过调节细菌的转录或翻译以及真核生物中的前mRNA剪接或多聚腺苷作用，对其同源小分子在细胞内的浓度做出反应。对于所研究的所有核糖开关类，系统发育序列分析描绘了一段高度保守的序列，这段序列对于特定的体外结合其同源代谢物是必要的和充分的。这些特定的结合域或适配子一直是研究核糖开关机制和功能的中心焦点。构象变化被认为是核糖开关功能的组成部分。小角X射线散射是一种探测这种构象变化的全局性的技术。最近，几个实验室发表了一些论文，利用这项技术来了解几种核糖开关RNA的代谢物诱导的结构反应。目前的提案与GUP12457和GUP11627有关，这两个提案的标题都是“调查拟议的各种核糖开关的‘切换’机制”。以前的GUP分配了波束时间，重点研究了拟议的核糖开关功能的一般特征。SAXS分析揭示了各种核糖开关对其各自的小分子效应物的特殊反应，如我们最近的出版物(Baird和Ferre-D‘Amare，RNA，2010；Kulshina等人，NSMB，2009)所述。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Current year GUP-21939: This GUP is a follow-up to GUP11627(2008) and GUP12457 (2009) in which we examined the proposed general features of riboswitch conformational change upon binding cognate small-molecules. Riboswitches are gene-regulatory mRNA domains that respond to the intracellular concentration of their cognate small molecules by modulating transcription or translation in bacteria and pre-mRNA splicing or polyadenylation in eukaryotes. For all riboswitch classes examined, phylogenetic sequence analyses delineate a segment of highly conserved sequence that is necessary and sufficient for specific in vitro binding to their cognate metabolites. These specific binding domains, or aptamers, have been the central focus of studies investigating riboswitch mechanism and function. Conformational changes are thought to be an integral part of riboswitch function. Small angle X-ray scattering is a technique to probe the global nature of such conformational changes. Recently, several labs have published papers utilizing this technique to understand the metabolite-induced structural response of several riboswitch RNA. The current proposal is related to GUP12457 and GUP11627, both entitled "Investigating the proposed 'switching' mechanism of various riboswitches". The previous GUPs, for which beamtime was allocated, focused on examining the proposed general features of riboswitch function. SAXS analyses revealed idiosyncratic responses of various riboswitches to their respective small-molecule effectors as described in our recent publications (Baird and Ferre-D'Amare, RNA, 2010; Kulshina et al, NSMB, 2009).