1TF7

Crystal Structure of Circadian Clock Protein KaiC


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.240 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Visualizing a Circadian Clock Protein; Crystal Structure of KaiC and Functional Insights

Pattanayek, R.Wang, J.Mori, T.Xu, Y.Johnson, C.H.Egli, M.

(2004) Mol Cell 15: 375-388

  • DOI: 10.1016/j.molcel.2004.07.013
  • Primary Citation of Related Structures:  
    1TF7

  • PubMed Abstract: 
  • Circadian (daily) biological clocks express characteristics that are difficult to explain by known biochemical mechanisms, and will ultimately require characterizing the structures, functions, and interactions of their molecular components. KaiC is a ...

    Circadian (daily) biological clocks express characteristics that are difficult to explain by known biochemical mechanisms, and will ultimately require characterizing the structures, functions, and interactions of their molecular components. KaiC is an essential circadian protein in cyanobacteria that forms the core of the KaiABC clock protein complex. We report the crystal structure of the KaiC homohexameric complex at 2.8 A resolution. The structure resembles a double doughnut with a central pore that is partially sealed at one end. The crystal structure reveals ATP binding, inter-subunit organization, a scaffold for Kai-protein complex formation, the location of critical KaiC mutations, and evolutionary relationships to other proteins. A key auto-phosphorylation site on KaiC (T432) is identified from the crystal structure, and mutation of this residue abolishes circadian rhythmicity. The crystal structure of KaiC will be essential for understanding this circadian clockwork and for establishing its links to global gene expression.


    Organizational Affiliation

    Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
KaiCABCDEF525Synechococcus sp.Mutation(s): 0 
Gene Names: PCC7942
EC: 2.7.11.1
Find proteins for Q79PF4 (Synechococcus elongatus (strain PCC 7942 / FACHB-805))
Explore Q79PF4 
Go to UniProtKB:  Q79PF4
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ATP
Query on ATP

Download CCD File 
A, B, C, D, E, F
ADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O13 P3
ZKHQWZAMYRWXGA-KQYNXXCUSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.240 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 132.873α = 90
b = 135.576β = 90
c = 204.951γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
GLRFphasing
CNSrefinement
MLPHAREphasing
RAVEphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-08-24
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance