Component of the cleavage and polyadenylation factor I (CF I)%3B CF 1%2C composed of the CF 1A complex (Rna14p%2C Rna15p%2C Clp1p%2C Pcf11p) and Hrp1%2C is involved in cleavage and polyadenylation of mRNA 3' ends%3B involved in both the endonucleolyitc cleavage and polyadenylation steps of mRNA 3'-end maturation and in gene looping which affects reinitiation of transcription