Halfter H, Gallwitz D
Max-Planck-Institute for Biophysical Chemistry, Department of Molecular Genetics, Göttingen, FRG.
Nucleic Acids Res. 1988 Nov 25;16(22):10413-23. doi: 10.1093/nar/16.22.10413.
The absolutely conserved TACTAAC box within introns of RNA polymerase II-transcribed genes of the yeast Saccharomyces cerevisiae serves an indispensable role in lariat formation. We show in this report that rather short palindromic sequences inserted into the yeast actin gene intron immediately 3' to the TACTAAC box block the second but not the first splicing step. In contrast, a palindromic sequence inserted some 23 bp 3' of the TACTAAC box did not affect correct and efficient splicing. The data suggest that hairpin structures that might form adjacent to the branchsite sequence interfere with some necessary alteration of the spliceosome required for 3' intron cleavage and exon ligation.
酵母酿酒酵母RNA聚合酶II转录基因内含子中的绝对保守的TACTAAC框在套索形成中起不可或缺的作用。我们在本报告中表明，插入酵母肌动蛋白基因内含子中紧接TACTAAC框下游3'的相当短的回文序列会阻断第二步而非第一步剪接步骤。相反，插入TACTAAC框下游约23 bp处的回文序列并不影响正确且高效的剪接。数据表明，可能在分支位点序列附近形成的发夹结构会干扰3'内含子切割和外显子连接所需的剪接体的某些必要改变。
