4P1Q | pdb_00004p1q

GREEN FLUORESCENT PROTEIN E222H VARIANT

• PDB DOI: https://doi.org/10.2210/pdb4P1Q/pdb

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


• Deposited: 2014-02-27 Released: 2014-07-16 
• Deposition Author(s): Klein, M., Carius, Y., Auerbach, D., Franz, S., Jung, G., Lancaster, C.R.D.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.50 Å
• R-Value Free: 
  0.172 (Depositor), 0.186 (DCC) 
• R-Value Work: 
  0.136 (Depositor) 
• R-Value Observed: 
  0.138 (Depositor) 

Literature

Replacement of Highly Conserved E222 by the Photostable Non-photoconvertible Histidine in GFP.

Auerbach, D., Klein, M., Franz, S., Carius, Y., Lancaster, C.R., Jung, G.

(2014) Chembiochem 15: 1404-1408

• PubMed: 24919579 
• DOI: https://doi.org/10.1002/cbic.201402075
• Primary Citation Related Structures: 
  4P1Q


• PubMed Abstract: 
  

  The widely used green fluorescent protein (GFP) decarboxylates upon irradiation; this involves removal of the acidic function of the glutamic acid at position 222, thereby resulting in the irreversible photoconversion of GFP. To suppress this phenomenon, the photostable, non-photoconvertible histidine was introduced at position 222 in GFP. The variant E222H shows negligible photodynamic processes and high expression yield. In addition, the stable and bright fluorescence over a wide pH range makes the E222H protein an alternative for GFP in fluorescence imaging and spectroscopy. Other fluorescent proteins are predicted to benefit from replacement of the catalytic glutamic acid by histidine.

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Organizational Affiliation: 
• Department of Biophysical Chemistry, Saarland University, Campus B22, 66123 Saarbrücken (Germany).

Biological Assembly 1  

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

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

Macromolecule Content 

• Total Structure Weight: 25.85 kDa 
• Atom Count: 2,181 
• Modeled Residue Count: 228 
• Deposited Residue Count: 228 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Green fluorescent protein	A	228	Aequorea victoria	Mutation(s): 3  Gene Names: GFP
UniProt
Find proteins for P42212 (Aequorea victoria) Explore P42212  Go to UniProtKB:  P42212

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
NA	B [auth A]	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
GYS	A	L-PEPTIDE LINKING	C14 H15 N3 O5		SER, TYR, GLY

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.50 Å
• R-Value Free:  0.172 (Depositor), 0.186 (DCC) 
• R-Value Work:  0.136 (Depositor) 
• R-Value Observed: 0.138 (Depositor) 

Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 50.6	α = 90
b = 62.2	β = 90
c = 67.57	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 2014-07-16 
Deposition Author(s): Klein, M., Carius, Y., Auerbach, D., Franz, S., Jung, G., Lancaster, C.R.D.

Revision History  

• Version 1.0: 2014-07-16
  Type: Initial release
  
• Version 1.1: 2015-01-21
  Changes: Structure summary
• Version 2.0: 2023-11-15
  Changes: Atomic model, Data collection, Database references, Derived calculations, Source and taxonomy
• Version 2.1: 2024-11-06
  Changes: Structure summary