3pyp
From Proteopedia
(New page: 200px<br /><applet load="3pyp" size="450" color="white" frame="true" align="right" spinBox="true" caption="3pyp, resolution 0.85Å" /> '''PHOTOACTIVE YELLOW P...) |
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| - | [[Image:3pyp.gif|left|200px]]<br /><applet load="3pyp" size=" | + | [[Image:3pyp.gif|left|200px]]<br /><applet load="3pyp" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="3pyp, resolution 0.85Å" /> | caption="3pyp, resolution 0.85Å" /> | ||
'''PHOTOACTIVE YELLOW PROTEIN, CRYOTRAPPED EARLY LIGHT CYCLE INTERMEDIATE'''<br /> | '''PHOTOACTIVE YELLOW PROTEIN, CRYOTRAPPED EARLY LIGHT CYCLE INTERMEDIATE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Protein photosensors from all kingdoms of life use bound organic | + | 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. |
==About this Structure== | ==About this Structure== | ||
| - | 3PYP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Halorhodospira_halophila Halorhodospira halophila] with HC4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 3PYP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Halorhodospira_halophila Halorhodospira halophila] with <scene name='pdbligand=HC4:'>HC4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3PYP OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Halorhodospira halophila]] | [[Category: Halorhodospira halophila]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Canestrelli, I | + | [[Category: Canestrelli, I L.]] |
| - | [[Category: Genick, U | + | [[Category: Genick, U K.]] |
| - | [[Category: Getzoff, E | + | [[Category: Getzoff, E D.]] |
[[Category: Kuhn, P.]] | [[Category: Kuhn, P.]] | ||
| - | [[Category: Soltis, S | + | [[Category: Soltis, S M.]] |
[[Category: HC4]] | [[Category: HC4]] | ||
[[Category: light sensor for negative phototaxis]] | [[Category: light sensor for negative phototaxis]] | ||
[[Category: photoreceptor]] | [[Category: photoreceptor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:11:06 2008'' |
Revision as of 17:11, 21 February 2008
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PHOTOACTIVE YELLOW PROTEIN, CRYOTRAPPED EARLY LIGHT CYCLE INTERMEDIATE
Overview
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.
About this Structure
3PYP is a Single protein structure of sequence from Halorhodospira halophila with as ligand. Full crystallographic information is available from OCA.
Reference
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
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