Polyadenylation of the 3ˊ end of eukaryotic pre-mRNA

Polyadenylation Polypeptide- coding sequence signal sequence Cleavage site l—l—l premRNA s'——Lu1a_ll 3' Start Stop codon codon 15—30 nucleotides 0 Cleavage and polyadenyl- ation complex assembles. 5’— 9 Pre—mRNA cleaved, leaving PAP at 3' end. S'— e 3’ fragment degraded in the nucleus. 0 PAP adds new adenines to 3’ end. 9 PABII molecules bind to increase rate of polyadenylation. 5'— AAAAAAAAAAAAAAAAAAAAAAAAAAAAA l Consensus Polypeptide- coding sequence sequence Poly- -A tail I—J—I l—l—l Pie—mRNA 5'——_m_m//_(_®JAAA 20-2 3’ Start Stop codon codon