1n9o: Difference between revisions

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New page: left|200px<br /><applet load="1n9o" size="450" color="white" frame="true" align="right" spinBox="true" caption="1n9o, resolution 2.8Å" /> '''Crystal structure of ...
 
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[[Image:1n9o.jpg|left|200px]]<br /><applet load="1n9o" size="450" color="white" frame="true" align="right" spinBox="true"  
[[Image:1n9o.jpg|left|200px]]<br /><applet load="1n9o" size="350" color="white" frame="true" align="right" spinBox="true"  
caption="1n9o, resolution 2.8&Aring;" />
caption="1n9o, resolution 2.8&Aring;" />
'''Crystal structure of the Phot-LOV1 domain from Chlamydomonas reinhardtii in illuminated state. Composite data set.'''<br />
'''Crystal structure of the Phot-LOV1 domain from Chlamydomonas reinhardtii in illuminated state. Composite data set.'''<br />


==Overview==
==Overview==
Phot proteins (phototropins and homologs) are blue-light photoreceptors, that control mechanical processes like phototropism, chloroplast, relocation, or guard-cell opening in plants. Phot receptors consist of two, flavin mononucleotide (FMN)-binding light, oxygen, or voltage (LOV), domains and a C-terminal serine/threonine kinase domain. We determined, crystal structures of the LOV1 domain of Phot1 from the green alga, Chlamydomonas reinhardtii in the dark and illuminated state to 1.9 A and, 2.8 A resolution, respectively. The structure resembles that of LOV2 from, Adiantum (Crosson, S. and K. Moffat. 2001. PROC: Natl. Acad. Sci. USA., 98:2995-3000). In the resting dark state of LOV1, the reactive Cys-57 is, present in two conformations. Blue-light absorption causes formation of a, proposed active signaling state that is characterized by a covalent bond, between the flavin C4a and the thiol of Cys-57. There are differences, around the FMN chromophore but no large overall conformational changes., Quantum chemical calculations based on the crystal structures revealed the, electronic distribution in the active site during the photocycle. The, results suggest trajectories for electrons, protons, and the active site, cysteine and offer an interpretation of the reaction mechanism.
Phot proteins (phototropins and homologs) are blue-light photoreceptors that control mechanical processes like phototropism, chloroplast relocation, or guard-cell opening in plants. Phot receptors consist of two flavin mononucleotide (FMN)-binding light, oxygen, or voltage (LOV) domains and a C-terminal serine/threonine kinase domain. We determined crystal structures of the LOV1 domain of Phot1 from the green alga Chlamydomonas reinhardtii in the dark and illuminated state to 1.9 A and 2.8 A resolution, respectively. The structure resembles that of LOV2 from Adiantum (Crosson, S. and K. Moffat. 2001. PROC: Natl. Acad. Sci. USA. 98:2995-3000). In the resting dark state of LOV1, the reactive Cys-57 is present in two conformations. Blue-light absorption causes formation of a proposed active signaling state that is characterized by a covalent bond between the flavin C4a and the thiol of Cys-57. There are differences around the FMN chromophore but no large overall conformational changes. Quantum chemical calculations based on the crystal structures revealed the electronic distribution in the active site during the photocycle. The results suggest trajectories for electrons, protons, and the active site cysteine and offer an interpretation of the reaction mechanism.


==About this Structure==
==About this Structure==
1N9O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Chlamydomonas_reinhardtii Chlamydomonas reinhardtii] with SO4 and FMN as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1N9O OCA].  
1N9O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Chlamydomonas_reinhardtii Chlamydomonas reinhardtii] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=FMN:'>FMN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N9O OCA].  


==Reference==
==Reference==
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[[Category: phototropin]]
[[Category: phototropin]]


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