Final answer:
SnRNP (U1) binding to the 5' splice site helps in the formation of a spliceosome, which catalyzes the precise removal of introns and ligation of exons to produce a mature mRNA ready for protein translation.
Step-by-step explanation:
After snRNP (U1) binds to the 5' splice site, it assists in bringing the two splice sites together to form a spliceosome. This complex, comprising of proteins and RNA molecules known as small nuclear RNAs (snRNAs), facilitates the process of splicing by precisely removing introns from the primary RNA transcript. The spliceosome catalyzes a series of cuts and ligations that result in the removal of the intron in the form of a lariat and the joining (ligation) of exons. This process ensures that the mature mRNA is ready for translation, with all codons intact and in the correct sequence to code for proteins.