CLONING OF CDNAS ENCODING THE 160 KDA SUBUNIT OF THE BOVINE CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR

3'-processing of mRNA precursors depends on several protein factors. O ne of them, cleavage and polyadenylation specificity factor (CPSF) is required for the cleavage of the mRNA precursor as well as for the tai l elongation reaction, We have obtained complementary DNA encoding the 160 kDa subunit, which had previously been shown to interact with the AAUAAA polyadenylation signal. The cDNAs code for an open reading fra me of 1444 amino acids, The translated protein has a calculated molecu lar weight of 161 kDa and a predicted pi of 6.2. Polyclonal antibodies raised against a bacterially expressed fragment of the cDNA recognise the 160 kDa subunit of purified calf thymus CPSF. The sequence contai ns a possible nuclear localisation signal but none of the known RNA bi nding motifs, It does, however, show sequence similarities to a UV-dam aged DNA binding protein (UVdDb.,