This superfamily entry represents the C-terminal Cdc73 (Cell division control protein 73) domain that plays role in transcription elongation. 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.

Cdc73 is an RNA polymerase II accessory factor PMID:8812838, and forms part of the Paf1 complex that has roles in post-initiation events PMID:9032243. The C-terminus adopts a Ras-like fold that is highly similar to GTPases of the Ras superfamily. 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 PMID:9891041.

INTERPRO:IPR031336, PFAM:PF05179,DOI:10.1074/jbc.M111.325647