2DD9: A Mutant Of Gfp-Like Protein From Chiridius Poppei

The fluorescence excitation and emission maxima of a GFP-like protein from the marine copepod Chiridius poppei (CpYGFP) show a significant red shift (lambda(ex) = 509 nm, lambda(em) = 517 nm) compared with those of GFP from Aequorea victoria (avGFP) and other GFP-like proteins from marine copepods. We performed crystallographic and biochemical studies to understand why this shift occurs in CpYGFP. The structure of CpYGFP showed that the imidazole side chain of His52 is involved in stacking on the phenol moiety of the chromophore. We investigated the potential role of His52 in causing the red-shifted spectral properties by performing mutational analyses of H52T, H52D and H52F. The emission wavelengths of H52T and H52D were blue-shifted and that of H52F was red-shifted relative to the wild type. Comparison of its structure of another copepod GFP (ppluGFP2) having an emission maximum at 502 nm showed that the imidazole ring of His54 (corresponding to His52 in CpYGFP) is flipped out of the stacking position with the chromophore. These findings suggest that pi-pi stacking interaction between His52 and the phenol moiety of the chromophore is the likely cause of the red-shift in light emission.
PDB ID: 2DD9Download
MMDB ID: 43680
PDB Deposition Date: 2006/1/24
Updated in MMDB: 2011/10
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 2DD9: dimeric; determined by author and by software (PISA)
Molecular Components in 2DD9
Label Count Molecule
Proteins (2 molecules)
Green Fluorescent Protein
Molecule annotation
Chemicals (5 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB