Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 26.79 kDa 
• Atom Count: 2161 
• Residue Count: 225 
• Unique protein chains: 1

2WSO

Structure of Cerulean Fluorescent Protein at physiological pH

• DOI: 10.2210/pdb2WSO/pdb

• Classification: FLUORESCENT PROTEIN
• Organism(s): Aequorea victoria
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2009-09-08 Released: 2009-09-29 
• Deposition Author(s): Lelimousin, M., Noirclerc-Savoye, M., Lazareno-Saez, C., Paetzold, B., Le Vot, S., Chazal, R., Macheboeuf, P., Field, M.J., Bourgeois, D., Royant, A.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.15 Å
• R-Value Free: 0.177 
• R-Value Work: 0.145 
• R-Value Observed: 0.147 

Literature

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

• PubMed: 19754158 
• DOI: 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.

---

Related Citations: 

• X-Ray Structure of Cerulean Gfp: A Tryptophan-Based Chromophore Useful for Fluorescence Lifetime Imaging.
  Malo, G.D., Pouwels, L.J., Wang, M., Weichsel, A., Montfort, W.R., Rizzo, M.A., Piston, D.W., Wachter, R.M.
  (2007) Biochemistry 46: 9865

---

Organizational Affiliation: 

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

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
GREEN FLUORESCENT PROTEIN	A	237	Aequorea victoria	Mutation(s): 1  Gene Names: GFP
Find proteins for P42212 (Aequorea victoria) Explore P42212  Go to UniProtKB:  P42212

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
CRF	A	L-PEPTIDE LINKING	C17 H18 N4 O4		THR, TRP, GLY

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.15 Å
• R-Value Free: 0.177 
• R-Value Work: 0.145 
• R-Value Observed: 0.147 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 50.99	α = 90
b = 62.81	β = 90
c = 69.49	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
XDS	data reduction
XSCALE	data scaling
MOLREP	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2009-09-08 
• Released Date: 2009-09-29 
Deposition Author(s): Lelimousin, M., Noirclerc-Savoye, M., Lazareno-Saez, C., Paetzold, B., Le Vot, S., Chazal, R., Macheboeuf, P., Field, M.J., Bourgeois, D., Royant, A.

Revision History 

• 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