InterPro domain: IPR007852

This entry includes Cdc73 from budding yeasts and its animal homologue, parafibromin. They are part of the Paf1 complex involved in histone modifications, transcription elongation and other gene expression processes that include transcript site selection [ 1 ].

In budding yeasts, Paf1 is an RNA polymerase II-associated protein complex containing Paf1, Cdc73, Ctr9, Rtf1 and Leo1. It is required for full expression of a subset of yeast genes, particularly those responsive to signals from the Pkc1/MAP kinase cascade. The complex appears to play an essential role in RNA elongation [ 2 ].

Human parafibromin is a tumour suppressor that may facilitate association of 3' mRNA processing factors with actively-transcribed chromatin. It is a component of the human Paf1 complex (Paf1C), which consists of Paf1, Cdc73, Ctr9, Rtf1, Leo1 and Wdr61 (Ski8). As in yeast, the human Paf1C has a central role in co-transcriptional histone modifications [ 3 ].

The Arabidopsis Cdc73 (also known as PLANT HOMOLOGOUS TO PARAFIBROMIN ,PHP) assists in regulating expression of genes within H3K27ME3-enriched chromatin [ 3 ] and participates in the modification of FLOWERING LOCUS C (FLC) chromatin [ 4 ].

1. The human PAF1 complex acts in chromatin transcription elongation both independently and cooperatively with SII/TFIIS. Cell 140, 491-503
2. RNA polymerase II elongation factors of Saccharomyces cerevisiae: a targeted proteomics approach. Mol. Cell. Biol. 22, 6979-92
3. PLANT HOMOLOGOUS TO PARAFIBROMIN is a component of the PAF1 complex and assists in regulating expression of genes within H3K27ME3-enriched chromatin. Plant Physiol. 153, 821-31
4. The Arabidopsis Paf1c complex component CDC73 participates in the modification of FLOWERING LOCUS C chromatin. Plant Physiol. 153, 1074-84