InterPro domain: IPR038103

CDC73 is an RNA polymerase II accessory factor [ 1 ], and forms part of the Paf1 complex that has roles in post-initiation events [ 2 ]. More specifically, crystal structure analysis shows the C terminus to be a Ras-like domain that adopts a fold that is highly similar to GTPases of the Ras superfamily. The C-terminal domain contains a large but comparatively flat surface of highly conserved residues, devoid of ligand. Deletion of the Cdc73 C-domain significantly reduces Paf1C occupancy on active genes, which means that the Cdc73 C-domain plays a role in promoting association of Paf1C with chromatin [ 3 ]. The canonical nucleotide binding pocket is altered in CDC73, and there is no nucleotide ligand, but it contributes to histone methylation and Paf1 complex (Paf1C) recruitment to active genes. Thus, together with Rtf1, it combines to couple Paf1C to elongating polymerase [ 4 ].

1. A novel collection of accessory factors associated with yeast RNA polymerase II. Protein Expr. Purif. 8, 85-90
2. Cdc73p and Paf1p are found in a novel RNA polymerase II-containing complex distinct from the Srbp-containing holoenzyme. Mol. Cell. Biol. 17, 1160-9
3. Cdc73 subunit of Paf1 complex contains C-terminal Ras-like domain that promotes association of Paf1 complex with chromatin. J Biol Chem 287, 10863-75
4. A complex containing RNA polymerase II, Paf1p, Cdc73p, Hpr1p, and Ccr4p plays a role in protein kinase C signaling. Mol. Cell. Biol. 19, 1056-67