Dönmez Gizem, Hartmuth Klaus, Kastner Berthold, Will Cindy L, Lührmann Reinhard
Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
Mol Cell. 2007 Feb 9;25(3):399-411. doi: 10.1016/j.molcel.2006.12.019.
Recognition and pairing of the correct 5' and 3' splice sites (ss) of a pre-mRNA are critical events that occur early during spliceosome assembly. Little is known about the spatial organization in early spliceosomal complexes of the U1 and U2 snRNPs, which together with several non-snRNP proteins, are involved in juxtapositioning the functional sites of the pre-mRNA. To better understand the molecular mechanisms of splice-site recognition/pairing, we have examined the organization of U2 relative to U1 and pre-mRNA in spliceosomal complexes via hydroxyl-radical probing with Fe-BABE-tethered U2 snRNA. These studies reveal that functional sites of the pre-mRNA are located close to the 5' end of U2 both in E and A complexes. U2 is also positioned close to U1 in a defined orientation already in the E complex, and their relative spatial organization remains largely unchanged during the E to A transition.
前体mRNA正确的5'和3'剪接位点（ss）的识别与配对是剪接体组装早期发生的关键事件。对于U1和U2小核核糖核蛋白（snRNP）在早期剪接体复合物中的空间组织了解甚少，它们与几种非snRNP蛋白一起参与前体mRNA功能位点的并列。为了更好地理解剪接位点识别/配对的分子机制，我们通过用Fe-BABE连接的U2小核RNA进行羟基自由基探测，研究了剪接体复合物中U2相对于U1和前体mRNA的组织情况。这些研究表明，在前体mRNA的功能位点在E复合物和A复合物中均靠近U2的5'端。在E复合物中，U2也已经以特定的方向靠近U1定位，并且在从E复合物到A复合物的转变过程中它们的相对空间组织基本保持不变。
