Catalysis of the second transesterification reaction of spliceosomal mRNA splicing. Ligation of the two exons occurs via a transesterification reaction where the free 3'-hydroxyl group of the 5' exon is the nucleophile attacking the 3' splice site. Non-expressed sequences are now detached from the exons. In cis splicing, the intron is in a lariat structure. (Gene Ontology, GO_0000386)
1 genes performing the second spliceosomal transesterification activity molecular function from the curated GO Molecular Function Annotations 2025 dataset.
