2IE2

The 1.7 A crystal structure of Dronpa: a photoswitchable green fluorescent protein

Summary for 2IE2

• Entry DOI: 10.2210/pdb2ie2/pdb
• Descriptor: Fluorescent protein Dronpa (2 entities in total)
• Functional Keywords: beta barrel, luminescent protein
• Biological source: Echinophyllia sp. SC22
• Total number of polymer chains: 6
• Total formula weight: 152987.42

Authors

Rossjohn, J.,Wilmann, P.G. (deposition date: 2006-09-16, release date: 2006-11-14, Last modification date: 2024-11-20)

Primary citation

Wilmann, P.G.,Turcic, K.,Battad, J.M.,Wilce, M.C.J.,Devenish, R.J.,Prescott, M.,Rossjohn, J.
The 1.7 A Crystal Structure of Dronpa: A Photoswitchable Green Fluorescent Protein
J.Mol.Biol., 364:213-224, 2006

PubMed Abstract: The green fluorescent protein (GFP), its variants, and the closely related GFP-like proteins possess a wide variety of spectral properties that are of widespread interest as biological tools. One desirable spectral property, termed photoswitching, involves the light-induced alteration of the optical properties of certain GFP members. Although the structural basis of both reversible and irreversible photoswitching events have begun to be unraveled, the mechanisms resulting in reversible photoswitching are less clear. A novel GFP-like protein, Dronpa, was identified to have remarkable light-induced photoswitching properties, maintaining an almost perfect reversible photochromic behavior with a high fluorescence to dark state ratio. We have crystallized and subsequently determined to 1.7 A resolution the crystal structure of the fluorescent state of Dronpa. The chromophore was observed to be in its anionic form, adopting a cis co-planar conformation. Comparative structural analysis of non-photoactivatable and photoactivatable GFPs, together with site-directed mutagenesis of a position (Cys62) within the Dronpa chromophore, has provided a basis for understanding Dronpa photoactivation. Specifically, we propose a model of reversible photoactivation whereby irradiation with light leads to subtle conformational changes within and around the environment of the chromophore that promotes proton transfer along an intricate polar network.

PubMed: 17010376
DOI: 10.1016/j.jmb.2006.08.089

Experimental method

X-RAY DIFFRACTION (1.7 Å)