Crystal structure of Calcium bound monomeric GCAMP2

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.163 
  • R-Value Observed: 0.166 

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Structural Basis for Calcium Sensing by GCaMP2.

Wang, Q.Shui, B.Kotlikoff, M.I.Sondermann, H.

(2008) Structure 16: 1817-1827

  • DOI: https://doi.org/10.1016/j.str.2008.10.008
  • Primary Citation of Related Structures:  
    3EVP, 3EVR, 3EVU, 3EVV

  • PubMed Abstract: 

    Genetically encoded Ca(2+) indicators are important tools that enable the measurement of Ca(2+) dynamics in a physiologically relevant context. GCaMP2, one of the most robust indicators, is a circularly permutated EGFP (cpEGFP)/M13/calmodulin (CaM) fusion protein that has been successfully used for studying Ca(2+) fluxes in vivo in the heart and vasculature of transgenic mice. Here we describe crystal structures of bright and dim states of GCaMP2 that reveal a sophisticated molecular mechanism for Ca(2+) sensing. In the bright state, CaM stabilizes the fluorophore in an ionized state similar to that observed in EGFP. Mutational analysis confirmed critical interactions between the fluorophore and elements of the fused peptides. Solution scattering studies indicate that the Ca(2+)-free form of GCaMP2 is a compact, predocked state, suggesting a molecular basis for the relatively rapid signaling kinetics reported for this indicator. These studies provide a structural basis for the rational design of improved Ca(2+)-sensitive probes.

  • Organizational Affiliation

    Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Myosin light chain kinase, Green fluorescent protein, Calmodulin-1 chimera411Aequorea victoriaRattus norvegicusMutation(s): 1 
Gene Names: GFPCalm1CalmCamCam1CaMI
Find proteins for P42212 (Aequorea victoria)
Explore P42212 
Go to UniProtKB:  P42212
Find proteins for P11799 (Gallus gallus)
Explore P11799 
Go to UniProtKB:  P11799
Find proteins for P0DP29 (Rattus norvegicus)
Explore P0DP29 
Go to UniProtKB:  P0DP29
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupsP42212P0DP29P11799
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.190 
  • R-Value Work: 0.163 
  • R-Value Observed: 0.166 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 121.995α = 90
b = 121.995β = 90
c = 97.831γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-12-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-07-26
    Changes: Advisory, Data collection, Database references, Refinement description, Source and taxonomy, Structure summary