6aly

Structural highlights

Function

[MED15_YEAST] Component of the Mediator complex, 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. 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. It has an important role in the negative regulation of Ty transcription.^{[1] [2] [3]}

References

1. ↑ Nair D, Kim Y, Myers LC. Mediator and TFIIH govern carboxyl-terminal domain-dependent transcription in yeast extracts. J Biol Chem. 2005 Oct 7;280(40):33739-48. Epub 2005 Aug 2. PMID:16076843 doi:http://dx.doi.org/M506067200
2. ↑ van de Peppel J, Kettelarij N, van Bakel H, Kockelkorn TT, van Leenen D, Holstege FC. Mediator expression profiling epistasis reveals a signal transduction pathway with antagonistic submodules and highly specific downstream targets. Mol Cell. 2005 Aug 19;19(4):511-22. PMID:16109375 doi:http://dx.doi.org/10.1016/j.molcel.2005.06.033
3. ↑ Takagi Y, Kornberg RD. Mediator as a general transcription factor. J Biol Chem. 2006 Jan 6;281(1):80-9. Epub 2005 Nov 1. PMID:16263706 doi:http://dx.doi.org/M508253200