The intron is removed in a Form callled a lariat(套马索)as o the Flanking Exons are joined u) Two successive transesterification a hthe branch site attacks the da 3 Step 1: The OH of the conserve o at t phoryl group of the conserved in the 5, splice site. As a result, the 5 exon is released and the send of the e. intron forms a three-way 总 Junction structureThe intron is removed in a Form Called a Lariat (套马索) as the Flanking Exons are joined Two successive transesterification: Step 1: The OH of the conserved A at the branch site attacks the phosphoryl group of the conserved G in the 5’ splice site. As a result, the 5’ exon is released and the 5’-end of the intron forms a three-way junction structure. The chemistry of RNA splicing