Structure of Enhanced Cyan Fluorescent Protein at physiological pH

Experimental Data Snapshot

  • Resolution: 1.37 Å
  • R-Value Free: 0.185 
  • R-Value Work: 0.140 
  • R-Value Observed: 0.142 

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This is version 1.4 of the entry. See complete history


Intrinsic Dynamics in Ecfp and Cerulean Control Fluorescence Quantum Yield.

Lelimousin, M.Noirclerc-Savoye, M.Lazareno-Saez, C.Paetzold, B.Le Vot, S.Chazal, R.Macheboeuf, P.Field, M.J.Bourgeois, D.Royant, A.

(2009) Biochemistry 48: 10038

  • DOI: https://doi.org/10.1021/bi901093w
  • Primary Citation of Related Structures:  
    2WSN, 2WSO

  • PubMed Abstract: 

    Enhanced cyan fluorescent protein (ECFP) and its variant Cerulean are genetically encoded fluorophores widely used as donors in FRET-based cell imaging experiments. First, we have confirmed through denaturation experiments that the double-peak spectroscopic signature of these fluorescent proteins originates from the indole ring of the chromophore. Then, to explain the improvement in the fluorescence properties of Cerulean compared to those of ECFP, we have determined the high-resolution crystal structures of these two proteins at physiological pH and performed molecular dynamics simulations. In both proteins, the N-terminal half of the seventh strand exhibits two conformations. These conformations both have a complex set of van der Waals interactions with the chromophore and, as our simulations suggest, they interconvert on a nanosecond time scale. The Y145A and H148D mutations in Cerulean stabilize these interactions and allow the chromophore to be more planar, better packed, and less prone to collisional quenching, albeit only intermittently. As a consequence, the probability of nonradiative decay is significantly decreased. Our results highlight the considerable dynamical flexibility that exists in the vicinity of the tryptophan-based chromophore of these engineered fluorescent proteins and provide insights that should allow the design of mutants with enhanced optical properties.

  • Organizational Affiliation

    Institut de Biologie Structurale Jean-Pierre Ebel, UMR 5075 CNRS-CEA-Universite Joseph Fourier, F-38027 Grenoble Cedex 1, France.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
GREEN FLUORESCENT PROTEIN237Aequorea victoriaMutation(s): 1 
Find proteins for P42212 (Aequorea victoria)
Explore P42212 
Go to UniProtKB:  P42212
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP42212
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on CRF
Experimental Data & Validation

Experimental Data

  • Resolution: 1.37 Å
  • R-Value Free: 0.185 
  • R-Value Work: 0.140 
  • R-Value Observed: 0.142 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.182α = 90
b = 62.72β = 90
c = 70.593γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2009-09-29
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2019-10-23
    Changes: Data collection, Database references, Derived calculations, Other
  • Version 1.4: 2023-12-20
    Changes: Data collection, Database references, Refinement description