1EMB

GREEN FLUORESCENT PROTEIN (GFP) FROM AEQUOREA VICTORIA, GLN 80 REPLACED WITH ARG


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.13 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.196 

Starting Model: experimental
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This is version 1.3 of the entry. See complete history


Literature

Structural basis for dual excitation and photoisomerization of the Aequorea victoria green fluorescent protein.

Brejc, K.Sixma, T.K.Kitts, P.A.Kain, S.R.Tsien, R.Y.Ormo, M.Remington, S.J.

(1997) Proc Natl Acad Sci U S A 94: 2306-2311

  • DOI: https://doi.org/10.1073/pnas.94.6.2306
  • Primary Citation of Related Structures:  
    1EMB

  • PubMed Abstract: 

    The 2.1-A resolution crystal structure of wild-type green fluorescent protein and comparison of it with the recently determined structure of the Ser-65 --> Thr (S65T) mutant explains the dual wavelength absorption and photoisomerization properties of the wild-type protein. The two absorption maxima are caused by a change in the ionization state of the chromophore. The equilibrium between these states appears to be governed by a hydrogen bond network that permits proton transfer between the chromophore and neighboring side chains. The predominant neutral form of the fluorophore maximally absorbs at 395 nm. It is maintained by the carboxylate of Glu-222 through electrostatic repulsion and hydrogen bonding via a bound water molecule and Ser-205. The ionized form of the fluorophore, absorbing at 475 nm, is present in a minor fraction of the native protein. Glu-222 donates its charge to the fluorophore by proton abstraction through a hydrogen bond network, involving Ser-205 and bound water. Further stabilization of the ionized state of the fluorophore occurs through a rearrangement of the side chains of Thr-203 and His-148. UV irradiation shifts the ratio of the two absorption maxima by pumping a proton relay from the neutral chromophore's excited state to Glu-222. Loss of the Ser-205-Glu-222 hydrogen bond and isomerization of neutral Glu-222 explains the slow return to the equilibrium dark-adapted state of the chromophore. In the S65T structure, steric hindrance by the extra methyl group stabilizes a hydrogen bonding network, which prevents ionization of Glu-222. Therefore the fluorophore is permanently ionized, causing only a 489-nm excitation peak. This new understanding of proton redistribution in green fluorescent protein should enable engineering of environmentally sensitive fluorescent indicators and UV-triggered fluorescent markers of protein diffusion and trafficking in living cells.


  • Organizational Affiliation

    Netherlands Cancer Institute, Department of Molecular Carcinogenesis, Amsterdam.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
GREEN FLUORESCENT PROTEIN236Aequorea victoriaMutation(s): 1 
UniProt
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
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
CRO
Query on CRO
A
L-PEPTIDE LINKINGC15 H17 N3 O5THR, TYR, GLY
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.13 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.196 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.9α = 90
b = 63.2β = 90
c = 68.8γ = 90
Software Package:
Software NamePurpose
TNTrefinement
MOSFLMdata reduction
CCP4data scaling
TNTphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-06-16
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-09
    Changes: Database references, Derived calculations, Refinement description