1R5P

Crystal Structure Analysis of KaiB from PCC7120

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.212 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history. 

Literature

Anabaena circadian clock proteins KaiA and KaiB reveal a potential common binding site to their partner KaiC

Garces, R.G., Wu, N., Gillon, W., Pai, E.F.

(2004) Embo J. 23: 1688-1698

  • DOI: 10.1038/sj.emboj.7600190
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • The cyanobacterial clock proteins KaiA and KaiB are proposed as regulators of the circadian rhythm in cyanobacteria. Mutations in both proteins have been reported to alter or abolish circadian rhythmicity. Here, we present molecular models of both Ka ...

    The cyanobacterial clock proteins KaiA and KaiB are proposed as regulators of the circadian rhythm in cyanobacteria. Mutations in both proteins have been reported to alter or abolish circadian rhythmicity. Here, we present molecular models of both KaiA and KaiB from the cyanobacteria Anabaena sp PCC7120 deduced by crystal structure analysis, and we discuss how clock-changing or abolishing mutations may cause their resulting circadian phenotype. The overall fold of the KaiA monomer is that of a four-helix bundle. KaiB, on the other hand, adopts an alpha-beta meander motif. Both proteins purify and crystallize as dimers. While the folds of the two proteins are clearly different, their size and some surface features of the physiologically relevant dimers are very similar. Notably, the functionally relevant residues Arg 69 of KaiA and Arg 23 of KaiB align well in space. The apparent structural similarities suggest that KaiA and KaiB may compete for a potential common binding site on KaiC.

    Organizational Affiliation: 

    Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
circadian oscillation regulator
A, B
108Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576)Gene Names: kaiB
Find proteins for Q8YT41 (Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576))
Go to UniProtKB:  Q8YT41
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.212 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 104.755α = 90.00
b = 36.387β = 98.83
c = 54.140γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
CNSrefinement
SOLVEphasing

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-05-04
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Source and taxonomy, Version format compliance