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1zp2
From Proteopedia
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| , resolution 3.0Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | srb11 (Schizosaccharomyces pombe) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of the Mediator subunit cyclin C
Overview
Cyclin C binds the cyclin-dependent kinases CDK8 and CDK3, which regulate mRNA transcription and the cell cycle, respectively. The crystal structure of cyclin C reveals two canonical five-helix repeats and a specific N-terminal helix. In contrast to other cyclins, the N-terminal helix is short, mobile, and in an exposed position that allows for interactions with proteins other than the CDKs. A model of the CDK8/cyclin C pair reveals two regions in the interface with apparently distinct roles. A conserved region explains promiscuous binding of cyclin C to CDK8 and CDK3, and a non-conserved region may be responsible for discrimination of CDK8 against other CDKs involved in transcription. A conserved and cyclin C-specific surface groove may recruit substrates near the CDK8 active site. Activation of CDKs generally involves phosphorylation of a loop at a threonine residue. In CDK8, this loop is longer and the threonine is absent, suggesting an alternative mechanism of activation that we discuss based on a CDK8-cyclin C model.
About this Structure
1ZP2 is a Single protein structure of sequence from Schizosaccharomyces pombe. Full crystallographic information is available from OCA.
Reference
Structure of the mediator subunit cyclin C and its implications for CDK8 function., Hoeppner S, Baumli S, Cramer P, J Mol Biol. 2005 Jul 29;350(5):833-42. PMID:15979093
Page seeded by OCA on Mon Mar 31 01:39:46 2008
