Just as transcription initiation and capping are coupled, transcription termination and the 3’ cleavage and polyadenylation reactions are functionally linked. The Cleavage/Polyadenylation reaction is carried out the polyadenylation complex, a large multi-protein complex assembled from CPSF, CStF, CF1, and CF2. What signals (i.e. RNA sequence) in a pre-mRNA specify the site of polyadenylation? Some pre-mRNA’s [...]

Eukaryotes encode long precursor RNA transcripts, which are spliced, polyadenylated and capped to produce a messenger RNA that can be translated. Capping Nucleus Guanosine is added to the 5′ end of the mRNA for stability, transport and translation initiation. Polyadenylation Nucleus The 3’ end of the RNA is cleaved and a Poly-A tail is added [...]