How does the spliceosome do its job?

The spliceosome recognizes specific sequences at the boundaries between exons and introns on the pre-mRNA. Its function is to cut out introns from pre-mRNA molecules through a series of chemical reactions. Pre-mRNA splicing is regulated by the spliceosome. This complex dictates interactions between RNA molecules and proteins, ensuring that the reactive sites on the pre-mRNA are aligned properly for splicing reactions to occur. The spliceosome assembles on the pre-mRNA at the splice sites. This assembly involves the recruitment of snRNPs and other protein factors. As the spliceosome assembles and acts on the pre-mRNA, it continually forms and reorganizes networks of RNA-RNA and RNA-protein interactions. The spliceosome involves constant changes in both structure and composition, allowing it to function with adaptability and precision. The spliceosome catalyzes two successive phosphoryl transfer reactions, leading to the cleavage of the intron-exon junctions and the ligation of the adjacent exons. Once splicing is complete, the components of the spliceosome are disassembled, releasing a mature mRNA, and can be reused.