1R8J

Crystal Structure of Circadian Clock Protein KaiA from Synechococcus elongatus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.03 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.213 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystal structure of circadian clock protein KaiA from Synechococcus elongatus

Ye, S.Vakonakis, I.Ioerger, T.R.LiWang, A.C.Sacchettini, J.C.

(2004) J Biol Chem 279: 20511-20518

  • DOI: 10.1074/jbc.M400077200
  • Primary Citation of Related Structures:  
    1R8J

  • PubMed Abstract: 
  • The circadian clock found in Synechococcus elongatus, the most ancient circadian clock, is regulated by the interaction of three proteins, KaiA, KaiB, and KaiC. While the precise function of these proteins remains unclear, KaiA has been shown to be a positive regulator of the expression of KaiB and KaiC ...

    The circadian clock found in Synechococcus elongatus, the most ancient circadian clock, is regulated by the interaction of three proteins, KaiA, KaiB, and KaiC. While the precise function of these proteins remains unclear, KaiA has been shown to be a positive regulator of the expression of KaiB and KaiC. The 2.0-A structure of KaiA of S. elongatus reported here shows that the protein is composed of two independently folded domains connected by a linker. The NH(2)-terminal pseudo-receiver domain has a similar fold with that of bacterial response regulators, whereas the COOH-terminal four-helix bundle domain is novel and forms the interface of the 2-fold-related homodimer. The COOH-terminal four-helix bundle domain has been shown to contain the KaiC binding site. The structure suggests that the KaiB binding site is covered in the dimer interface of the KaiA "closed" conformation, observed in the crystal structure, which suggests an allosteric regulation mechanism.


    Organizational Affiliation

    Center for Structural Biology, Institute of Biosciences and Technology, Houston, TX 77030, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
KaiAA, B289Synechococcus elongatus PCC 7942 = FACHB-805Mutation(s): 0 
Gene Names: kaiASynpcc7942_1218see0009
UniProt
Find proteins for Q79PF6 (Synechococcus elongatus (strain PCC 7942 / FACHB-805))
Explore Q79PF6 
Go to UniProtKB:  Q79PF6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ79PF6
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.03 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.213 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.111α = 90
b = 125.818β = 114.9
c = 56.818γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
SHARPphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-06-01
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance