真核生物mRNA二级结构与内含子剪接

Secondary Structures of mRNAs and Splicing of Introns in Eukaryotes.

对６８ 个外显子内含子外显子序列片段以及相应的外显子外显子序列片段的二级结构进行分析后发现，内含子５′端和３′端的碱基 Ｇ （ 剪接位点） 中大约９０ ％ 位于二级结构的环区或是茎区的端部并靠近环， 而且位于环区的 Ｇ 也多靠近环的基部； ９２ ％ 的外显子拼接位点也有类似性质． 约８２ ％ 的分枝点 Ａ 位于环区或环与茎的连接部位．

After analyzing the secondary structures of 68 exon intron exon and the corresponding exon exon sequence segments, it is found that about 90% of 5′ and 3′ terminal bases G (splicing sites) of introns are situated in the loops of secondary structures or at the ends of stems near the loops, and most of “G”s in loops are closed to the ends of loops. Approximately 92% of the connecting sites of the adjoining exons also show the similar features. About 82% of the branch point “A”s are situated in loops or at the ends of stems near the loops. Splicing sites and branch points approach each other in space because of the folding.