2GBL

Crystal Structure of Full Length Circadian Clock Protein KaiC with Phosphorylation Sites


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.290 
  • R-Value Work: 0.230 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Analysis of KaiA-KaiC protein interactions in the cyano-bacterial circadian clock using hybrid structural methods.

Pattanayek, R.Williams, D.R.Pattanayek, S.Xu, Y.Mori, T.Johnson, C.H.Stewart, P.L.Egli, M.

(2006) Embo J. 25: 2017-2028

  • DOI: 10.1038/sj.emboj.7601086

  • PubMed Abstract: 
  • The cyanobacterial circadian clock can be reconstituted in vitro by mixing recombinant KaiA, KaiB and KaiC proteins with ATP, producing KaiC phosphorylation and dephosphorylation cycles that have a regular rhythm with a ca. 24-h period and are temper ...

    The cyanobacterial circadian clock can be reconstituted in vitro by mixing recombinant KaiA, KaiB and KaiC proteins with ATP, producing KaiC phosphorylation and dephosphorylation cycles that have a regular rhythm with a ca. 24-h period and are temperature-compensated. KaiA and KaiB are modulators of KaiC phosphorylation, whereby KaiB antagonizes KaiA's action. Here, we present a complete crystallographic model of the Synechococcus elongatus KaiC hexamer that includes previously unresolved portions of the C-terminal regions, and a negative-stain electron microscopy study of S. elongatus and Thermosynechococcus elongatus BP-1 KaiA-KaiC complexes. Site-directed mutagenesis in combination with EM reveals that KaiA binds exclusively to the CII half of the KaiC hexamer. The EM-based model of the KaiA-KaiC complex reveals protein-protein interactions at two sites: the known interaction of the flexible C-terminal KaiC peptide with KaiA, and a second postulated interaction between the apical region of KaiA and the ATP binding cleft on KaiC. This model brings KaiA mutation sites that alter clock period or abolish rhythmicity into contact with KaiC and suggests how KaiA might regulate KaiC phosphorylation.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Circadian clock protein kinase kaiC
A, B, E, F
519Synechococcus elongatus (strain PCC 7942)Mutation(s): 0 
Gene Names: kaiC
EC: 2.7.11.1
Find proteins for Q79PF4 (Synechococcus elongatus (strain PCC 7942))
Go to UniProtKB:  Q79PF4
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Circadian clock protein kinase kaiC
C, D
519Synechococcus elongatus (strain PCC 7942)Mutation(s): 0 
Gene Names: kaiC
EC: 2.7.11.1
Find proteins for Q79PF4 (Synechococcus elongatus (strain PCC 7942))
Go to UniProtKB:  Q79PF4
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ATP
Query on ATP

Download SDF File 
Download CCD File 
A, B, C, D, E, F
ADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O13 P3
ZKHQWZAMYRWXGA-KQYNXXCUSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B, C, D, E, F
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP
A, B, E, F
L-PEPTIDE LINKINGC3 H8 N O6 PSER
TPO
Query on TPO
A, B, C, D, E, F
L-PEPTIDE LINKINGC4 H10 N O6 PTHR
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.290 
  • R-Value Work: 0.230 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 132.873α = 90.00
b = 135.576β = 90.00
c = 204.951γ = 90.00
Software Package:
Software NamePurpose
RAVEphasing
DENZOdata reduction
CNSrefinement
SCALEPACKdata scaling
Ravemodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-01-23
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Source and taxonomy, Version format compliance