1w7u

Photoproduct of the Wild-Type Aequorea victoria Green Fluorescent Protein after structural annealing at 170K

spinqualitylabelsall models 1w7u, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1w7u is a 4 chain structure with sequence from Aequorea victoria. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.85Å Ligands: ABA, GYS Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GFP_AEQVI Energy-transfer acceptor. Its role is to transduce the blue chemiluminescence of the protein aequorin into green fluorescent light by energy transfer. Fluoresces in vivo upon receiving energy from the Ca(2+)-activated photoprotein aequorin. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Green fluorescent protein (GFP) fluoresces efficiently under blue excitation despite major electrostatic rearrangements resulting from photoionization of the chromophore and neutralization of Glu-222. A competing phototransformation process, which ionizes the chromophore and decarboxylates Glu-222, mimics the electrostatic and structural changes in the fluorescence photocycle. Structural and spectroscopic analysis of the cryogenically stabilized photoproduct at 100 K and a structurally annealed intermediate of the phototransformed protein at 170 K reveals distinct structural relaxations involving protein, chromophore, solvent, and photogenerated CO2. Strong structural changes of the 100 K photoproduct after decarboxylation appear exclusively within 15 angstroms of the chromophore and include the electrostatically driven perturbations of Gln-69, Cys-70, and water molecules in an H-bonding network connecting the chromophore. X-ray crystallography to 1.85 angstroms resolution and static and picosecond time-resolved IR spectroscopy identify structural mechanisms common to phototransformation and to the fluorescence photocycle. In particular, the appearance of a 1697 cm(-1) (+) difference band in both photocycle and phototransformation intermediates is a spectroscopic signature for the structural perturbation of Gln-69. This is taken as evidence for an electrostatically driven dynamic response that is common to both photoreaction pathways. The interactions between the chromophore and the perturbed residues and solvent are decreased or removed in the T203H single and T203H/Q69L double mutants, resulting in a strong reduction of the fluorescence quantum yield. This suggests that the electrostatic response to the transient formation of a buried charge in the wild type is important for the bright fluorescence. Ultrafast and low barrier motions in the photoreactions of the green fluorescent protein.,van Thor JJ, Georgiev GY, Towrie M, Sage JT J Biol Chem. 2005 Sep 30;280(39):33652-9. Epub 2005 Jul 20. PMID:16033764 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Green Fluorescent Protein 3D structures

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