InterPro domain: IPR021643

This entry represents the N-terminal domain of Med13.

Mediator is a large complex of up to 33 proteins that is conserved from plants through fungi to humans - the number and representation of individual subunits varying with species [ 1 , 2 ]. It is arranged into four different sections, a core, a head, a tail and a kinase-activity part, and the number of subunits within each of these is what varies with species. Overall, Mediator regulates the transcriptional activity of RNA polymerase II but it would appear that each of the four different sections has a slightly different function. Med13 is part of the ancillary kinase module, together with Med12, CDK8 and CycC, which in yeast is implicated in transcriptional repression, though most of this activity is likely attributable to the CDK8 kinase. The large Med12 and Med13 proteins are required for specific developmental processes in Drosophila [ 3 ], zebrafish, and Caenorhabditis elegans but their biochemical functions are not understood [ 4 ].

1. TRAP230/ARC240 and TRAP240/ARC250 Mediator subunits are functionally conserved through evolution. Proc. Natl. Acad. Sci. U.S.A. 100, 6422-7
2. A unified nomenclature for protein subunits of mediator complexes linking transcriptional regulators to RNA polymerase II. Mol. Cell 14, 553-7
3. Distinct roles for Mediator Cdk8 module subunits in Drosophila development. EMBO J. 26, 1045-54
4. Pygopus activates Wingless target gene transcription through the mediator complex subunits Med12 and Med13. Proc. Natl. Acad. Sci. U.S.A. 105, 6644-9