SAXS ON TRANSCRIPTION FACTOR IIF ASSOCIAT C-TERMINAL REPEAT DOMAIN PHOSPHATASE

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。 项目1-RNA聚合酶II的转录终止是由通用转录因子IIF(TFIIF)和TFIIF相关的C末端重复结构域磷酸酶(FCP1)相互作用推动的。核磁共振和圆二色谱表明，FCP1的酸性C-端区在游离态是无序的，但与TFIIF重链结合后呈螺旋构象。我们最近利用~(13)C检测的核磁共振波谱产生了游离ctFCP1(残基879-961)的全面的核磁共振化学位移，对这些数据的二次位移分析表明，尽管CD结果表明缺乏持久的螺旋结构，但平衡系综偏向于残基945-960的螺旋构象。我们的目标是通过获取相同879-961结构上的SAXS数据，进一步限制ctFCP1溶液系综的整体水动力形状。 项目2-我们最近解决了绵羊肝脏山梨醇脱氢酶(SORD)的晶体结构。早期的研究证实，哺乳动物SORD中的氢键网络稳定了四聚体状态，对于催化能力是必不可少的。我们的晶体结构不支持这种四聚体的形成。我们有兴趣检查在溶液中形成的低聚物是否与我们的晶体结构匹配。

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. Project 1 - Termination of transcription by RNA polymerase II is promoted by an interaction between the general transcription factor IIF (TFIIF) and the TFIIF-associating C-terminal repeat domain phosphatase (FCP1). The acidic C-terminal region of FCP1 is disordered in the free state, as indicated by NMR and CD spectroscopy, but adopts an ¿¿-helical conformation upon binding to the heavy chain of TFIIF. We have recently utilized 13C-detected NMR spectroscopy to generate comprehensive NMR chemical shifts of free ctFCP1 (residues 879-961) and secondary shift analysis of these data suggest that the equilibrium ensemble is biased towards ¿¿-helical conformation in residues 945-960 ¿¿" the TFIIF associating peptide ¿¿" despite the lack of persistent helical structure indicated by the CD results. We aim to gain further constraint on the overall hydrodynamic shape of the ctFCP1 solution ensemble through acquisition of SAXS data on the same 879-961 construct. Project 2 - We have recently solved the crystal structure of sheep liver sorbitol dehydrogenase (SORD). Earlier studies have confirmed that a hydrogen bonding network in mammalian SORD stabilizes a tetrameric state and is essential for the catalytic power. Our crystal structure does not support such a tetramer formation. We are interested in checking if the oligomer formed in solution matches with our crystal structure.