Abstract:
The initial pre-mRNA transcript in eukaryotes is processed by a large multi-protein complex in order to correctly cleave the 3\' end, and to subsequently add the polyadenosine tail. This cleavage and polyadenylation specificity factor (CPSF) is composed of separate subunits, with structural information available for both isolated subunits and also larger assembled complexes. Nevertheless, certain key components of CPSF still lack high-resolution atomic data. One such region is the heterodimer formed between the first and second C-terminal domains of the endonuclease CPSF73, with those from the catalytically inactive CPSF100. Here we report the backbone and sidechain resonance assignments of a minimal C-terminal heterodimer of CPSF73-CPSF100 derived from the parasite Encephalitozoon cuniculi. The assignment process used several amino-acid specific labeling strategies, and the chemical shift values allow for secondary structure prediction.
摘要:
真核生物中的初始pre-mRNA转录物通过大的多蛋白复合物进行处理,以便正确地切割3'末端,并随后添加聚腺苷尾。这种切割和聚腺苷酸化特异性因子(CPSF)由单独的亚基组成,具有分离的亚基和更大的组装复合物的结构信息。然而,CPSF的某些关键组件仍然缺乏高分辨率的原子数据。一个这样的区域是在核酸内切酶CPSF73的第一和第二C末端结构域之间形成的异二聚体,与来自催化失活的CPSF100的那些。在这里,我们报告了源自寄生虫头孢菌素cuniculi的CPSF73-CPSF100的最小C端异二聚体的主链和侧链共振分配。分配过程使用了几种氨基酸特异性标记策略,和化学位移值允许二级结构预测。