1YKH

Structure of the mediator MED7/MED21 (Med7/Srb7) subcomplex

Summary for 1YKH

• Entry DOI: 10.2210/pdb1ykh/pdb
• Related: 1YKE
• Descriptor: RNA polymerase II mediator complex protein MED7, RNA polymerase II holoenzyme component SRB7 (2 entities in total)
• Functional Keywords: gene regulation
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Cellular location: Nucleus: Q08278 P47822
• Total number of polymer chains: 2
• Total formula weight: 28279.53

Authors

Baumli, S.,Hoeppner, S.,Cramer, P. (deposition date: 2005-01-18, release date: 2005-02-22, Last modification date: 2024-05-29)

Primary citation

Baumli, S.,Hoeppner, S.,Cramer, P.
A conserved mediator hinge revealed in the structure of the MED7.MED21 (Med7.Srb7) heterodimer.
J.Biol.Chem., 280:18171-18178, 2005

PubMed Abstract: The Mediator of transcriptional regulation is the central coactivator that enables a response of RNA polymerase II (Pol II) to activators and repressors. We present the 3.0-A crystal structure of a highly conserved part of the Mediator, the MED7.MED21 (Med7.Srb7) heterodimer. The structure is very extended, spanning one-third of the Mediator length and almost the diameter of Pol II. It shows a four-helix bundle domain and a coiled-coil protrusion connected by a flexible hinge. Four putative protein binding sites on the surface allow for assembly of the Mediator middle module and for binding of the conserved subunit MED6, which is shown to bridge to the Mediator head module. A flexible MED6 bridge and the MED7.MED21 hinge could account for changes in overall Mediator structure upon binding to Pol II or activators. Our results support the idea that transcription regulation involves conformational changes within the general machinery.

PubMed: 15710619
DOI: 10.1074/jbc.M413466200

Experimental method

X-RAY DIFFRACTION (3 Å)