2ie2
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The 1.7 A crystal structure of Dronpa: a photoswitchable green fluorescent protein
OverviewOverview
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.
About this StructureAbout this Structure
2IE2 is a Single protein structure of sequence from Echinophyllia sp. sc22. Full crystallographic information is available from OCA.
ReferenceReference
The 1.7 A crystal structure of Dronpa: a photoswitchable green fluorescent protein., Wilmann PG, Turcic K, Battad JM, Wilce MC, Devenish RJ, Prescott M, Rossjohn J, J Mol Biol. 2006 Nov 24;364(2):213-24. Epub 2006 Sep 3. PMID:17010376
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