This family consists of several eukaryotic suppressor of forked (Suf) like proteins. The Drosophila melanogaster Suppressor of forked [Su(f)] protein shares homology with the yeast RNA14 protein and the 77-kDa subunit of human cleavage stimulation factor, which are proteins involved in mRNA 3' end formation. This suggests a role for Su(f) in mRNA 3' end formation in Drosophila. The su(f) gene produces three transcripts; two of them are polyadenylated at the end of the transcription unit, and one is a truncated transcript, polyadenylated in intron 4. It is thought that su(f) plays a role in the regulation of poly(A) site utilisation and an important role of the GU-rich sequence for this regulation to occur.