This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
2hzm
From Proteopedia
| |||||||
| , resolution 2.4Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | SRB2, HRS2, MED20 (Saccharomyces cerevisiae), SRB5, MED18 (Saccharomyces cerevisiae) | ||||||
| Related: | 1ZP2, 1YKE, 1YKH, 2HZS
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of the Mediator head subcomplex Med18/20
Overview
The Mediator head module stimulates basal RNA polymerase II (Pol II) transcription and enables transcriptional regulation. Here we show that the head subunits Med8, Med18 and Med20 form a subcomplex (Med8/18/20) with two submodules. The highly conserved N-terminal domain of Med8 forms one submodule that binds the TATA box-binding protein (TBP) in vitro and is essential in vivo. The second submodule consists of the C-terminal region of Med8 (Med8C), Med18 and Med20. X-ray analysis of this submodule reveals that Med18 and Med20 form related beta-barrel folds. A conserved putative protein-interaction face on the Med8C/18/20 submodule includes sites altered by srb mutations, which counteract defects resulting from Pol II truncation. Our results and published data support a positive role of the Med8/18/20 subcomplex in initiation-complex formation and suggest that the Mediator head contains a multipartite TBP-binding site that can be modulated by transcriptional activators.
About this Structure
2HZM is a Protein complex structure of sequences from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
Structure and TBP binding of the Mediator head subcomplex Med8-Med18-Med20., Lariviere L, Geiger S, Hoeppner S, Rother S, Strasser K, Cramer P, Nat Struct Mol Biol. 2006 Oct;13(10):895-901. Epub 2006 Sep 10. PMID:16964259
Page seeded by OCA on Mon Mar 31 03:37:41 2008
