3RJ1

Architecture of the Mediator Head module

Summary for 3RJ1

• Entry DOI: 10.2210/pdb3rj1/pdb
• Related: 2HZM 2HZS
• Descriptor: Mediator of RNA polymerase II transcription subunit 11, Mediator of RNA polymerase II transcription subunit 17, Mediator of RNA polymerase II transcription subunit 8, ... (8 entities in total)
• Functional Keywords: mediator, rna polymeras ii, pol ii, rnap, med, head module, mediator head, regulator, helical bundle, transcriptional regulation, rna polymerase ii, tbp, nucleus, transcription
• Biological source: Saccharomyces cerevisiae (brewer's yeast,lager beer yeast,yeast); More
• Cellular location: Nucleus : Q99278 P32569 P38304 P32570 P32585 P34162 P38782
• Total number of polymer chains: 21
• Total formula weight: 636188.70

Authors

Imasaki, T.,Calero, G.,Cai, G.,Tsai, K.L.,Yamada, K.,Cardelli, F.,Erdjument-Bromage, H.,Tempst, P.,Berger, I.,Kornberg, G.L.,Asturias, F.J.,Kornberg, R.D.,Takagi, Y. (deposition date: 2011-04-14, release date: 2011-07-27, Last modification date: 2024-11-06)

Primary citation

Imasaki, T.,Calero, G.,Cai, G.,Tsai, K.L.,Yamada, K.,Cardelli, F.,Erdjument-Bromage, H.,Tempst, P.,Berger, I.,Kornberg, G.L.,Asturias, F.J.,Kornberg, R.D.,Takagi, Y.
Architecture of the Mediator head module.
Nature, 475:240-243, 2011

PubMed Abstract: Mediator is a key regulator of eukaryotic transcription, connecting activators and repressors bound to regulatory DNA elements with RNA polymerase II (Pol II). In the yeast Saccharomyces cerevisiae, Mediator comprises 25 subunits with a total mass of more than one megadalton (refs 5, 6) and is organized into three modules, called head, middle/arm and tail. Our understanding of Mediator assembly and its role in regulating transcription has been impeded so far by limited structural information. Here we report the crystal structure of the essential Mediator head module (seven subunits, with a mass of 223 kilodaltons) at a resolution of 4.3 ångströms. Our structure reveals three distinct domains, with the integrity of the complex centred on a bundle of ten helices from five different head subunits. An intricate pattern of interactions within this helical bundle ensures the stable assembly of the head subunits and provides the binding sites for general transcription factors and Pol II. Our structural and functional data suggest that the head module juxtaposes transcription factor IIH and the carboxy-terminal domain of the largest subunit of Pol II, thereby facilitating phosphorylation of the carboxy-terminal domain of Pol II. Our results reveal architectural principles underlying the role of Mediator in the regulation of gene expression.

PubMed: 21725323
DOI: 10.1038/nature10162

Experimental method

X-RAY DIFFRACTION (4.3 Å)