Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Structure of the mediator subunit cyclin C and its implications for CDK8 function.

Sabine Hoeppner1, Sonja Baumli, Patrick Cramer

  • 1Gene Center, University of Munich (LMU), Department of Chemistry and Biochemistry, Feodor-Lynen-Str. 25, 81377 Munich, Germany.

Journal of Molecular Biology
|June 28, 2005
PubMed
Summary

Cyclin C’s unique structure, particularly its N-terminal helix, enables interactions beyond cyclin-dependent kinases (CDKs). This structural insight reveals novel mechanisms for CDK regulation and substrate recruitment in transcription and cell cycle control.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Transcription initiation drives dosage compensation establishment and maintenance in male <i>Drosophila</i>.

Science advances·2026
Same author

Mechanism of co-transcriptional cap snatching by influenza polymerase.

Nature·2026
Same author

Molecular mechanism of co-transcriptional H3K36 methylation by SETD2.

Nature communications·2025
Same author

IWS1 positions downstream DNA to globally stimulate Pol II elongation.

Nature communications·2025
Same author

Chemical crosslinking extends and complements UV crosslinking in analysis of RNA/DNA nucleic acid-protein interaction sites by mass spectrometry.

Nucleic acids research·2025
Same author

Structure of a transcribing Pol II-DSIF-SPT6-U1 snRNP complex.

Nature communications·2025

Area of Science:

  • Molecular Biology
  • Structural Biology
  • Biochemistry

Background:

  • Cyclin C is a regulatory protein that binds cyclin-dependent kinases (CDKs) CDK3 and CDK8.
  • CDK3 regulates the cell cycle, while CDK8 controls mRNA transcription.
  • Understanding Cyclin C's structure and interactions is crucial for elucidating these regulatory processes.

Purpose of the Study:

  • To determine the crystal structure of Cyclin C.
  • To model the CDK8/Cyclin C complex and understand their interaction interface.
  • To investigate the structural basis for Cyclin C's binding specificity and CDK activation.

Main Methods:

  • X-ray crystallography was used to determine the structure of Cyclin C.
  • Computational modeling was employed to create a model of the CDK8/Cyclin C complex.

Related Experiment Videos

  • Structural analysis focused on conserved and non-conserved regions at the interface and potential substrate recruitment sites.

    • Main Results:

    • The Cyclin C crystal structure revealed two canonical five-helix repeats and a unique, short, mobile N-terminal helix.
    • The CDK8/Cyclin C model identified distinct interface regions responsible for binding promiscuity and CDK8 specificity.
    • A conserved surface groove on Cyclin C may recruit substrates to the CDK8 active site, and CDK8 lacks the typical activating threonine residue.

    Conclusions:

    • Cyclin C's N-terminal helix facilitates interactions with non-CDK proteins.
    • The structural interface explains Cyclin C's binding to CDK3 and CDK8 and CDK8's specificity.
    • Alternative activation mechanisms for CDK8 are suggested, distinct from canonical CDK activation pathways.