2H9W

Green fluorescent protein ground states: the influence of a second protonation site near the chromophore


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.82 Å
  • R-Value Free: 0.186 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.167 

wwPDB Validation   3D Report Full Report


This is version 1.6 of the entry. See complete history


Literature

Green Fluorescent Protein Ground States: The Influence of a Second Protonation Site near the Chromophore.

Bizzarri, R.Nifosi, R.Abbruzzetti, S.Rocchia, W.Guidi, S.Arosio, D.Garau, G.Campanini, B.Grandi, E.Ricci, F.Viappiani, C.Beltram, F.

(2007) Biochemistry 46: 5494-5504

  • DOI: https://doi.org/10.1021/bi602646r
  • Primary Citation of Related Structures:  
    2H9W

  • PubMed Abstract: 

    The photophysical properties of most green fluorescent protein mutants (GFPs) are strongly affected by pH. This effect must be carefully taken into account when using GFPs as fluorescent probes or indicators. Usually, the pH-dependence of GFPs is rationalized on the basis of the ionization equilibrium of the chromophore phenol group. Yet many different mutants show spectral behavior that cannot be explained by ionization of this group alone. In this study, we propose a general model of protonation comprising two ionization sites (2S model). Steady-state optical measurements at different pH and temperature and pH-jump relaxation experiments were combined to highlight the thermodynamic and kinetic properties of paradigmatically different GFP variants. Our experiments support the 2S model. For the case of mutants in which E222 is the second protonation site, thermodynamic coupling between this residue's and the chromophore's ionization reactions was demonstrated. In agreement with the 2S model predictions, X-ray analysis of one of these mutants showed the presence of two chromophore populations at high pH.


  • Organizational Affiliation

    Scuola Normale Superiore-IIT Research Unit, Piazza dei Cavalieri 7 I-56126 Pisa, Italy. r.bizzarri@ sns.it


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Green fluorescent protein238Aequorea victoriaMutation(s): 4 
Gene Names: GFP
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  2 Unique
IDChains TypeFormula2D DiagramParent
CRO
Query on CRO
A
L-PEPTIDE LINKINGC15 H17 N3 O5THR, TYR, GLY
CSD
Query on CSD
A
L-PEPTIDE LINKINGC3 H7 N O4 SCYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.82 Å
  • R-Value Free: 0.186 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.167 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.886α = 90
b = 62.933β = 90
c = 71.035γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
CCP4model building
REFMACrefinement
CCP4data scaling
CCP4phasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Released Date: 2007-04-24 
  • Deposition Author(s): Garau, G.

Revision History  (Full details and data files)

  • Version 1.0: 2007-04-24
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2014-11-12
    Changes: Structure summary
  • Version 1.4: 2021-10-20
    Changes: Advisory, Database references, Derived calculations
  • Version 1.5: 2023-08-30
    Changes: Data collection, Refinement description
  • Version 1.6: 2023-11-15
    Changes: Data collection