3pyp

PHOTOACTIVE YELLOW PROTEIN, CRYOTRAPPED EARLY LIGHT CYCLE INTERMEDIATE

spinqualitylabelsall models 3pyp, resolution 0.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3pyp is a 1 chain structure with sequence from Halorhodospira halophila. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: HC4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PYP_HALHA] Photoactive blue light protein. Probably functions as a photoreceptor for a negative phototaxis response. 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 Protein photosensors from all kingdoms of life use bound organic molecules, known as chromophores, to detect light. A specific double bond within each chromophore is isomerized by light, triggering slower changes in the protein as a whole. The initial movements of the chromophore, which can occur in femtoseconds, are tightly constrained by the surrounding protein, making it difficult to see how isomerization can occur, be recognized, and be appropriately converted into a protein-wide structural change and biological signal. Here we report how this dilemma is resolved in the photoactive yellow protein (PYP). We trapped a key early intermediate in the light cycle of PYP at temperatures below -100 degrees C, and determined its structure at better than 1 A resolution. The 4-hydroxycinnamoyl chromophore isomerizes by flipping its thioester linkage with the protein, thus avoiding collisions resulting from large-scale movement of its aromatic ring during the initial light reaction. A protein-to-chromophore hydrogen bond that is present in both the preceding dark state and the subsequent signalling state of the photosensor breaks, forcing one of the hydrogen-bonding partners into a hydrophobic pocket. The isomerized bond is distorted into a conformation resembling that in the transition state. The resultant stored energy is used to drive the PYP light cycle. These results suggest a model for phototransduction, with implications for bacteriorhodopsin, photoactive proteins, PAS domains, and signalling proteins. Structure at 0.85 A resolution of an early protein photocycle intermediate.,Genick UK, Soltis SM, Kuhn P, Canestrelli IL, Getzoff ED Nature. 1998 Mar 12;392(6672):206-9. PMID:9515969 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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