Mammalian Clock Protein mPER2 - Crystal Structure of a PAS Domain Fragment

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.224 
  • R-Value Observed: 0.264 

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Structural and functional analyses of PAS domain interactions of the clock proteins Drosophila PERIOD and mouse PERIOD2.

Hennig, S.Strauss, H.M.Vanselow, K.Yildiz, O.Schulze, S.Arens, J.Kramer, A.Wolf, E.

(2009) PLoS Biol 7: e94-e94

  • DOI: https://doi.org/10.1371/journal.pbio.1000094
  • Primary Citation of Related Structures:  
    3GDI, 3GEC

  • PubMed Abstract: 

    PERIOD proteins are central components of the Drosophila and mammalian circadian clocks. The crystal structure of a Drosophila PERIOD (dPER) fragment comprising two PER-ARNT-SIM (PAS) domains (PAS-A and PAS-B) and two additional C-terminal alpha-helices (alphaE and alphaF) has revealed a homodimer mediated by intermolecular interactions of PAS-A with tryptophane 482 in PAS-B and helix alphaF. Here we present the crystal structure of a monomeric PAS domain fragment of dPER lacking the alphaF helix. Moreover, we have solved the crystal structure of a PAS domain fragment of the mouse PERIOD homologue mPER2. The mPER2 structure shows a different dimer interface than dPER, which is stabilized by interactions of the PAS-B beta-sheet surface including tryptophane 419 (equivalent to Trp482dPER). We have validated and quantitatively analysed the homodimer interactions of dPER and mPER2 by site-directed mutagenesis using analytical gel filtration, analytical ultracentrifugation, and co-immunoprecipitation experiments. Furthermore we show, by yeast-two-hybrid experiments, that the PAS-B beta-sheet surface of dPER mediates interactions with TIMELESS (dTIM). Our study reveals quantitative and qualitative differences between the homodimeric PAS domain interactions of dPER and its mammalian homologue mPER2. In addition, we identify the PAS-B beta-sheet surface as a versatile interaction site mediating mPER2 homodimerization in the mammalian system and dPER-dTIM heterodimer formation in the Drosophila system.

  • Organizational Affiliation

    Max Planck Institute of Molecular Physiology, Department of Structural Biology, Dortmund, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Period circadian protein homolog 2
A, B
309Mus musculusMutation(s): 0 
Gene Names: Per2
UniProt & NIH Common Fund Data Resources
Find proteins for O54943 (Mus musculus)
Explore O54943 
Go to UniProtKB:  O54943
IMPC:  MGI:1195265
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO54943
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.224 
  • R-Value Observed: 0.264 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.67α = 90
b = 63.38β = 102.25
c = 72.51γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PDB_EXTRACTdata extraction
MAR345data collection
XDSdata scaling
XDSdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-05-19
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2016-12-14
    Changes: Structure summary
  • Version 1.3: 2017-11-01
    Changes: Refinement description
  • Version 1.4: 2023-09-06
    Changes: Data collection, Database references, Refinement description