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| | ==Crystal structure of obelin following Ca2+ triggered bioluminescence suggests neutral coelenteramide as the primary excited state== | | ==Crystal structure of obelin following Ca2+ triggered bioluminescence suggests neutral coelenteramide as the primary excited state== |
| - | <StructureSection load='2f8p' size='340' side='right' caption='[[2f8p]], [[Resolution|resolution]] 1.93Å' scene=''> | + | <StructureSection load='2f8p' size='340' side='right'caption='[[2f8p]], [[Resolution|resolution]] 1.93Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2f8p]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Black_sea_hydrozoan Black sea hydrozoan]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2F8P OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2F8P FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2f8p]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Obelia_longissima Obelia longissima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2F8P OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2F8P FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CEI:N-[3-BENZYL-5-(4-HYDROXYPHENYL)PYRAZIN-2-YL]-2-(4-HYDROXYPHENYL)ACETAMIDE'>CEI</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]] 1.93Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1el4|1el4]], [[1jf0|1jf0]], [[1jf2|1jf2]], [[1qv0|1qv0]], [[1sl7|1sl7]], [[1s36|1s36]]</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CEI:N-[3-BENZYL-5-(4-HYDROXYPHENYL)PYRAZIN-2-YL]-2-(4-HYDROXYPHENYL)ACETAMIDE'>CEI</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">OBELIN ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=32570 Black sea hydrozoan])</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=2f8p FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2f8p OCA], [https://pdbe.org/2f8p PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2f8p RCSB], [https://www.ebi.ac.uk/pdbsum/2f8p PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2f8p ProSAT], [https://www.topsan.org/Proteins/SECSG/2f8p TOPSAN]</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=2f8p FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2f8p OCA], [http://pdbe.org/2f8p PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2f8p RCSB], [http://www.ebi.ac.uk/pdbsum/2f8p PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2f8p ProSAT], [http://www.topsan.org/Proteins/SECSG/2f8p TOPSAN]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/OBL_OBELO OBL_OBELO]] Ca(2+)-dependent bioluminescence photoprotein. Displays an emission peak at 470 nm (blue light). Trace amounts of calcium ion trigger the intramolecular oxidation of the chromophore, coelenterazine into coelenteramide and CO(2) with the concomitant emission of light. | + | [https://www.uniprot.org/uniprot/OBL_OBELO OBL_OBELO] Ca(2+)-dependent bioluminescence photoprotein. Displays an emission peak at 470 nm (blue light). Trace amounts of calcium ion trigger the intramolecular oxidation of the chromophore, coelenterazine into coelenteramide and CO(2) with the concomitant emission of light. |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Black sea hydrozoan]] | + | [[Category: Large Structures]] |
| - | [[Category: Lee, J]] | + | [[Category: Obelia longissima]] |
| - | [[Category: Liu, Z J]] | + | [[Category: Lee J]] |
| - | [[Category: Structural genomic]] | + | [[Category: Liu ZJ]] |
| - | [[Category: Stepanyuk, G A]] | + | [[Category: Stepanyuk GA]] |
| - | [[Category: Vysotski, E S]] | + | [[Category: Vysotski ES]] |
| - | [[Category: Wang, B C]] | + | [[Category: Wang BC]] |
| - | [[Category: Helix-turn-helix]]
| + | |
| - | [[Category: Luminescent protein]]
| + | |
| - | [[Category: PSI, Protein structure initiative]]
| + | |
| - | [[Category: Secsg]]
| + | |
| Structural highlights
Function
OBL_OBELO Ca(2+)-dependent bioluminescence photoprotein. Displays an emission peak at 470 nm (blue light). Trace amounts of calcium ion trigger the intramolecular oxidation of the chromophore, coelenterazine into coelenteramide and CO(2) with the concomitant emission of light.
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
The crystal structure at 1.93-A resolution is determined for the Ca2+-discharged obelin containing three bound calcium ions as well as the product of the bioluminescence reaction, coelenteramide. This finding extends the series of available spatial structures of the ligand-dependent conformations of the protein to four, the obelin itself, and those after the bioluminescence reaction with or without bound Ca2+ and/or coelenteramide. Among these structures, global conformational changes are small, typical of the class of "calcium signal modulators" within the EF-hand protein superfamily. Nevertheless, in the active site there are significant repositions of two residues. The His-175 imidazole ring flips becoming almost perpendicular to the original orientation corroborating the crucial importance of this residue for triggering bioluminescence. Tyr-138 hydrogen bonded to the coelenterazine N1-atom in unreacted obelin is moved away from the binding cavity after reaction. However, this Tyr is displaced by a water molecule from within the cavity, which now forms a hydrogen bond to the same atom, the amide N of coelenteramide. From this observation, a reaction scheme is proposed that would result in the neutral coelenteramide as the primary excited state product in photoprotein bioluminescence. From such a higher energy state it is now energetically feasible to account for the shorter wavelength bioluminescence spectra obtained from some photoprotein mutants or to populate the lower energy state of the phenolate anion to yield the blue bioluminescence ordinarily observed from native photoproteins.
Crystal structure of obelin after Ca2+-triggered bioluminescence suggests neutral coelenteramide as the primary excited state.,Liu ZJ, Stepanyuk GA, Vysotski ES, Lee J, Markova SV, Malikova NP, Wang BC Proc Natl Acad Sci U S A. 2006 Feb 21;103(8):2570-5. Epub 2006 Feb 8. PMID:16467137[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Liu ZJ, Stepanyuk GA, Vysotski ES, Lee J, Markova SV, Malikova NP, Wang BC. Crystal structure of obelin after Ca2+-triggered bioluminescence suggests neutral coelenteramide as the primary excited state. Proc Natl Acad Sci U S A. 2006 Feb 21;103(8):2570-5. Epub 2006 Feb 8. PMID:16467137
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