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| | <StructureSection load='5tv0' size='340' side='right'caption='[[5tv0]], [[Resolution|resolution]] 1.65Å' scene=''> | | <StructureSection load='5tv0' size='340' side='right'caption='[[5tv0]], [[Resolution|resolution]] 1.65Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5tv0]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Syny3 Syny3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5TV0 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5TV0 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5tv0]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Synechocystis_sp._PCC_6803_substr._Kazusa Synechocystis sp. PCC 6803 substr. Kazusa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5TV0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5TV0 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EQ3:(3R)-3-HYDROXY-BETA,BETA-CAROTEN-4-ONE'>EQ3</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.648Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5tuw|5tuw]], [[5tux|5tux]]</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EQ3:(3R)-3-HYDROXY-BETA,BETA-CAROTEN-4-ONE'>EQ3</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">slr1963 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1111708 SYNY3])</td></tr> | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5tv0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5tv0 OCA], [https://pdbe.org/5tv0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5tv0 RCSB], [https://www.ebi.ac.uk/pdbsum/5tv0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5tv0 ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5tv0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5tv0 OCA], [http://pdbe.org/5tv0 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5tv0 RCSB], [http://www.ebi.ac.uk/pdbsum/5tv0 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5tv0 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/OCP_SYNY3 OCP_SYNY3]] Acts as a photo-protectant. Essential for inhibiting white and blue-green light non-photochemical quenching (NPQ). Binding carotenoids improves OCP's intrinsic photoprotectant activity by broadening its absorption spectrum and facilitating the dissipation of absorbed energy.<ref>PMID:16531492</ref> | + | [https://www.uniprot.org/uniprot/OCP_SYNY3 OCP_SYNY3] Acts as a photo-protectant. Essential for inhibiting white and blue-green light non-photochemical quenching (NPQ). Binding carotenoids improves OCP's intrinsic photoprotectant activity by broadening its absorption spectrum and facilitating the dissipation of absorbed energy.<ref>PMID:16531492</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Syny3]] | + | [[Category: Synechocystis sp. PCC 6803 substr. Kazusa]] |
| - | [[Category: Bandara, S]] | + | [[Category: Bandara S]] |
| - | [[Category: Ren, Z]] | + | [[Category: Ren Z]] |
| - | [[Category: Yang, X]] | + | [[Category: Yang X]] |
| - | [[Category: Carotenoid binding protein]]
| + | |
| - | [[Category: Dynamic crystallography]]
| + | |
| - | [[Category: Photoprotection]]
| + | |
| - | [[Category: Photoreceptor]]
| + | |
| Structural highlights
Function
OCP_SYNY3 Acts as a photo-protectant. Essential for inhibiting white and blue-green light non-photochemical quenching (NPQ). Binding carotenoids improves OCP's intrinsic photoprotectant activity by broadening its absorption spectrum and facilitating the dissipation of absorbed energy.[1]
Publication Abstract from PubMed
Photoprotection is essential for efficient photosynthesis. Cyanobacteria have evolved a unique photoprotective mechanism mediated by a water-soluble carotenoid-based photoreceptor known as orange carotenoid protein (OCP). OCP undergoes large conformational changes in response to intense blue light, and the photoactivated OCP facilitates dissipation of excess energy via direct interaction with allophycocyanins at the phycobilisome core. However, the structural events leading up to the OCP photoactivation remain elusive at the molecular level. Here we present direct observations of light-induced structural changes in OCP captured by dynamic crystallography. Difference electron densities between the dark and illuminated states reveal widespread and concerted atomic motions that lead to altered protein-pigment interactions, displacement of secondary structures, and domain separation. Based on these crystallographic observations together with site-directed mutagenesis, we propose a molecular mechanism for OCP light perception, in which the photochemical property of a conjugated carbonyl group is exploited. We hypothesize that the OCP photoactivation starts with keto-enol tautomerization of the essential 4-keto group in the carotenoid, which disrupts the strong hydrogen bonds between the bent chromophore and the protein moiety. Subsequent structural changes trapped in the crystal lattice offer a high-resolution glimpse of the initial molecular events as OCP begins to transition from the orange-absorbing state to the active red-absorbing state.
Photoactivation mechanism of a carotenoid-based photoreceptor.,Bandara S, Ren Z, Lu L, Zeng X, Shin H, Zhao KH, Yang X Proc Natl Acad Sci U S A. 2017 Jun 13;114(24):6286-6291. doi:, 10.1073/pnas.1700956114. Epub 2017 May 30. PMID:28559328[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wilson A, Ajlani G, Verbavatz JM, Vass I, Kerfeld CA, Kirilovsky D. A soluble carotenoid protein involved in phycobilisome-related energy dissipation in cyanobacteria. Plant Cell. 2006 Apr;18(4):992-1007. Epub 2006 Mar 10. PMID:16531492 doi:10.1105/tpc.105.040121
- ↑ Bandara S, Ren Z, Lu L, Zeng X, Shin H, Zhao KH, Yang X. Photoactivation mechanism of a carotenoid-based photoreceptor. Proc Natl Acad Sci U S A. 2017 Jun 13;114(24):6286-6291. doi:, 10.1073/pnas.1700956114. Epub 2017 May 30. PMID:28559328 doi:http://dx.doi.org/10.1073/pnas.1700956114
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