Controlled dynamic remodeling of the spliceosome active site enables the first step of splicing

Proceedings of the National Academy of Sciences, Volume 123, Issue 1, January 2026. <br/>SignificanceRNA splicing removes noncoding regions from precursor mRNAs, a process essential to produce functional transcripts in all living organisms. In eukaryotes, this reaction is catalyzed by the spliceosome, a dynamic RNA–protein complex that …