描述Cwc2,U6 snRNA和Prp8相互作用的特征,这些相互作用在剪接的第一步和第二步之间过渡时被Prp16 ATPase破坏稳定
Jadwiga Meissner1,2, Katarzyna Eysmont1, Katarzyna Matylla-Kulińska
1IMol, Polish Academy of Sciences, 02-247 Warsaw, Poland.
概括
拼接体在拼接步骤之间重新排列其催化中心. Prp16 ATPase,Cwc2,Prp8和U6 RNA调节了这个过程,揭示了spliceosome催化作用的关键相互作用.
科学领域:
- 分子生物学分子生物学
- 在RNA生物学,RNA生物学.
- 生物化学 生物化学
背景情况:
- 拼接体是一个动态的分子机器,负责mRNA前拼接.
- 它在单个催化中心内催化两个连续的转化反应,需要进行构造性重新排列.
- Prp16 ATPase对于促进从第一个到第二个催化步骤的过渡至关重要.
研究的目的:
- 调查支离子体催化中心重排的基础分子机制.
- 识别和描述调节Prp16 ATPase功能的因素.
- 阐明Cwc2的作用,Prp8的N端域和U6 snRNA在结合体催化中的作用.
主要方法:
- 基因选用于识别Cwc2,Prp8和U6 snRNA突变基因,这些基因抑制prp16-302突变的缺陷.
- 分析了冷电子显微镜 (cryo-EM) 结构,以评估结合体催化中心内已识别的等位基因的近距离.
- 评估了已识别的因素与内子序列的相互作用及其对催化步骤稳定性的贡献.
主要成果:
- 鉴定出了Cwc2,Prp8和U6 snRNA的几个等位基因,可以纠正prp16-302.2的催化缺陷.
- 这些等位基因彼此附近聚集在结合体的冷EM结构中.
- 在第一个拼接步骤中,Cwc2和U6 snRNA主要与内子序列相互作用,而Prp8 N-终端段通过稳定催化构造来影响两个步骤.
结论:
- Cwc2,Prp8和U6 snRNA在调节结合体催化中心重组中起着不同的作用.
- Prp8的N端域对于在两种拼接步骤中保持催化中心的完整性至关重要.
- 这些发现提供了对结合体催化 conformations 和过渡状态的结构特征的见解.
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