This repeat is found in Pre-mRNA cleavage complex 2 protein Pcf11 from human (Swiss:O94913) and similar proteins from vertebrates. This repeat is about thirteen amino acids with a high content of proline and glycine residues, however, it varies in length among the sequences included in this entry. These repeats contain the highly conserved RFE/DG motif, conserved in PCF11 orthologues in vertebrates but not in Drosophila, C. elegans, or yeast [3]. It has been described that human PCF11 has 30 repeats of the RFE/DG motif (referred as FEGP in [3]) which are necessary for pre-mRNA cleavage complex II (CFII) activity [3]. PCF11 is a subunit and an essential component of CFII (the orthologue of cleavage and polyadenylation factor IA (CFIA) from yeast) which is involved in pre-mRNA 3' end processing and in transcription termination [1]. PCF11 is thought to be one of the scaffold proteins of the processing complex. PCF11-mediated termination is essential for vertebrate development [2].

1: The interaction of Pcf11 and Clp1 is needed for mRNA 3'-end formation and is modulated by amino acids in the ATP-binding site. Ghazy MA, Gordon JM, Lee SD, Singh BN, Bohm A, Hampsey M, Moore C; Nucleic Acids Res. 2012;40:1214-1225. PMID:21993299

2: Selective Roles of Vertebrate PCF11 in Premature and Full-Length Transcript Termination. Kamieniarz-Gdula K, Gdula MR, Panser K, Nojima T, Monks J, Wisniewski JR, Riepsaame J, Brockdorff N, Pauli A, Proudfoot NJ; Mol Cell. 2019;74:158-172. PMID:30819644

3: Reconstitution of mammalian cleavage factor II involved in 3' processing of mRNA precursors. Schafer P, Tuting C, Schonemann L, Kuhn U, Treiber T, Treiber N, Ihling C, Graber A, Keller W, Meister G, Sinz A, Wahle E; RNA. 2018;24:1721-1737. PMID:30139799