IPR020998
Mediator of RNA polymerase II transcription subunit 3
InterPro entry
Short name | Med3 |
Description
Med3 is a subunit of the RNA polymerase II mediator complex. It is a direct target of Cyc8-Tup1 transcriptional corepressor
[1].
The Mediator complex is a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. The Mediator complex, having a compact conformation in its free form, is recruited to promoters by direct interactions with regulatory proteins and serves for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors. On recruitment the Mediator complex unfolds to an extended conformation and partially surrounds RNA polymerase II, specifically interacting with the unphosphorylated form of the C-terminal domain (CTD) of RNA polymerase II. The Mediator complex dissociates from the RNA polymerase II holoenzyme and stays at the promoter when transcriptional elongation begins.
The Mediator complex is composed of at least 31 subunits: MED1, MED4, MED6, MED7, MED8, MED9, MED10, MED11, MED12, MED13, MED13L, MED14, MED15, MED16, MED17, MED18, MED19, MED20, MED21, MED22, MED23, MED24, MED25, MED26, MED27, MED29, MED30, MED31, CCNC, CDK8 and CDC2L6/CDK11.
References
1.Hrs1/Med3 is a Cyc8-Tup1 corepressor target in the RNA polymerase II holoenzyme. Papamichos-Chronakis M, Conlan RS, Gounalaki N, Copf T, Tzamarias D. J. Biol. Chem. 275, 8397-403, (2000). View articlePMID: 10722672
GO terms
biological process
molecular function
cellular component
Contributing Member Database Entry
- Pfam:PF11593