CPSF plays a key role in pre-mRNA 3'-end formation, recognizing the AAUAAA signal sequence and interacting with poly(A) polymerase and other factors to bring about cleavage and poly(A) addition. In X.laevis this subunit seems to be predominantly involved in cytoplasmic polyadenylation reaction. May also be involved in the histone 3'-end pre-mRNA processing. CPSF is a heterotetramer composed of four distinct subunits 160, 100, 70 and 30 kDa (By similarity). Identification in a complex with cpsf2, cpsf73, cpsf160 and sympk. Interacts with sympk. Belongs to the metallo-beta-lactamase superfamily. RNA-metabolizing metallo-beta-lactamase-like family. CPSF2/YSH1 subfamily.