Pikielny C W, Teem J L, Rosbash M
Cell. 1983 Sep;34(2):395-403. doi: 10.1016/0092-8674(83)90373-2.
Sequence comparison of the introns of two yeast genes (rp51A and rp51B) coding for the same ribosomal protein shows homology only in the last 50 bases of the intron. This region of the intron contains an internal conserved sequence (ICS) present near the 3' end of all sequenced yeast nuclear mRNA introns. Removal of a 29 bp sequence containing the ICS prevents splicing of an intron-containing hybrid gene. In cells containing the wild-type gene, we have detected RNA molecules that we suggest are normal splicing intermediates, generated by an endonucleolytic cut in the primary transcript at the ICS. The homology of the ICS with a sequence near the 5' end of U1 snRNA suggests a model in which an interaction in cis between the ICS and the 5' splice junction in yeast is the counterpart of the interaction in trans between U1 and 5' splice junctions in higher eucaryotes.
对编码相同核糖体蛋白的两个酵母基因（rp51A和rp51B）的内含子进行序列比较，结果显示内含子仅在最后50个碱基处具有同源性。内含子的这一区域包含一个内部保守序列（ICS），该序列存在于所有已测序的酵母核mRNA内含子的3'端附近。去除包含ICS的29 bp序列会阻止含内含子的杂交基因的剪接。在含有野生型基因的细胞中，我们检测到了一些RNA分子，我们认为这些分子是正常的剪接中间体，是由初级转录本在ICS处的内切核酸酶切割产生的。ICS与U1 snRNA 5'端附近序列的同源性提示了一种模型，即酵母中ICS与5'剪接位点之间的顺式相互作用是高等真核生物中U1与5'剪接位点之间反式相互作用的对应物。
