| Primary Identifier | IPR009401 | Type | Domain |
| Short Name | Med13_C |
| description | This entry represents the C-terminal domain of Med13. This domain is also identified as an RNaseH domain of the medPIWI PIWI/Argonaute module. medPIWI is the core domain found in the Med13 protein. The medPIWI module in Med13 is predicted to bind double-stranded nucleic acids, triggering the experimentally-observed conformational switch in the CDK8 subcomplex which regulates the Mediator complex []. Med13 is a component of the SRB8-11 complex. The SRB8-11 complex is a regulatory module of the Mediator complex, which may be involved in the transcriptional repression of a subset of genes regulated by Mediator. It acts by inhibiting the association of the Mediator complex with RNA polymerase II to form the holoenzyme complex [].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. |
