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| | ==Crystal structure of allophycocyanin B from Synechocystis PCC 6803== | | ==Crystal structure of allophycocyanin B from Synechocystis PCC 6803== |
| - | <StructureSection load='4po5' size='340' side='right' caption='[[4po5]], [[Resolution|resolution]] 1.75Å' scene=''> | + | <StructureSection load='4po5' size='340' side='right'caption='[[4po5]], [[Resolution|resolution]] 1.75Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4po5]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Synechocystis_sp. Synechocystis sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4PO5 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4PO5 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4po5]] is a 6 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=4PO5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4PO5 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CYC:PHYCOCYANOBILIN'>CYC</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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]] 1.751Å</td></tr> |
| - | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MEN:N-METHYL+ASPARAGINE'>MEN</scene></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CYC:PHYCOCYANOBILIN'>CYC</scene>, <scene name='pdbligand=MEN:N-METHYL+ASPARAGINE'>MEN</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></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=4po5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4po5 OCA], [http://pdbe.org/4po5 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4po5 RCSB], [http://www.ebi.ac.uk/pdbsum/4po5 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4po5 ProSAT]</span></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=4po5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4po5 OCA], [https://pdbe.org/4po5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4po5 RCSB], [https://www.ebi.ac.uk/pdbsum/4po5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4po5 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/PHAC_SYNY3 PHAC_SYNY3]] Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex. Allophycocyanin has a maximum absorption at approximately 654 nanometers (By similarity). [[http://www.uniprot.org/uniprot/PHAB_SYNY3 PHAB_SYNY3]] Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex. Allophycocyanin has a maximum absorption at approximately 650 nanometers. | + | [https://www.uniprot.org/uniprot/APCD_SYNY3 APCD_SYNY3] Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex. Allophycocyanin has a maximum absorption at approximately 654 nanometers (By similarity).[REFERENCE:2] |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | ==See Also== | | ==See Also== |
| - | *[[Allophycocyanin|Allophycocyanin]] | + | *[[Allophycocyanin 3D structures|Allophycocyanin 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Synechocystis sp]] | + | [[Category: Large Structures]] |
| - | [[Category: Ding, W L]] | + | [[Category: Synechocystis sp. PCC 6803 substr. Kazusa]] |
| - | [[Category: Dong, L L]] | + | [[Category: Ding WL]] |
| - | [[Category: Pang, P P]] | + | [[Category: Dong LL]] |
| - | [[Category: Scheer, H]] | + | [[Category: Pang PP]] |
| - | [[Category: Sun, Y F]] | + | [[Category: Scheer H]] |
| - | [[Category: Yang, X]] | + | [[Category: Sun YF]] |
| - | [[Category: Zeng, X L]] | + | [[Category: Yang X]] |
| - | [[Category: Zhao, K H]] | + | [[Category: Zeng XL]] |
| - | [[Category: Alpha-helical phycobiliprotein]]
| + | [[Category: Zhao KH]] |
| - | [[Category: Light harvesting]]
| + | |
| - | [[Category: Methylation on asn71 in apcb subunit]]
| + | |
| - | [[Category: Photosynthesis]]
| + | |
| - | [[Category: Phycobilisome]]
| + | |
| - | [[Category: Phycocyanobilin]]
| + | |
| Structural highlights
Function
APCD_SYNY3 Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex. Allophycocyanin has a maximum absorption at approximately 654 nanometers (By similarity).[REFERENCE:2]
Publication Abstract from PubMed
Allophycocyanin B (AP-B) is one of the two terminal emitters in phycobilisomes, the unique light-harvesting complexes of cyanobacteria and red algae. Its low excitation-energy level and the correspondingly redshifted absorption and fluorescence emission play an important role in funnelling excitation energy from the hundreds of chromophores of the extramembraneous phycobilisome to the reaction centres within the photosynthetic membrane. In the absence of crystal structures of these low-abundance terminal emitters, the molecular basis for the extreme redshift and directional energy transfer is largely unknown. Here, the crystal structure of trimeric AP-B [(ApcD/ApcB)3] from Synechocystis sp. PCC 6803 at 1.75 A resolution is reported. In the crystal lattice, eight trimers of AP-B form a porous, spherical, 48-subunit assembly of 193 A in diameter with an internal cavity of 1.1 x 10(6) A(3). While the overall structure of trimeric AP-B is similar to those reported for many other phycobiliprotein trimers, the chromophore pocket of the alpha-subunit, ApcD, has more bulky residues that tightly pack the phycocyanobilin (PCB). Ring D of the chromophores is further stabilized by close interactions with ApcB from the adjacent monomer. The combined contributions from both subunits render the conjugated rings B, C and D of the PCB in ApcD almost perfectly coplanar. Together with mutagenesis data, it is proposed that the enhanced planarity effectively extends the conjugation system of PCB and leads to the redshifted absorption (lambdamax = 669 nm) and fluorescence emission (679 nm) of the ApcD chromophore in AP-B, thereby enabling highly efficient energy transfer from the phycobilisome core to the reaction centres.
The structure of allophycocyanin B from Synechocystis PCC 6803 reveals the structural basis for the extreme redshift of the terminal emitter in phycobilisomes.,Peng PP, Dong LL, Sun YF, Zeng XL, Ding WL, Scheer H, Yang X, Zhao KH Acta Crystallogr D Biol Crystallogr. 2014 Oct 1;70(Pt 10):2558-69. doi:, 10.1107/S1399004714015776. Epub 2014 Sep 27. PMID:25286841[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Peng PP, Dong LL, Sun YF, Zeng XL, Ding WL, Scheer H, Yang X, Zhao KH. The structure of allophycocyanin B from Synechocystis PCC 6803 reveals the structural basis for the extreme redshift of the terminal emitter in phycobilisomes. Acta Crystallogr D Biol Crystallogr. 2014 Oct 1;70(Pt 10):2558-69. doi:, 10.1107/S1399004714015776. Epub 2014 Sep 27. PMID:25286841 doi:http://dx.doi.org/10.1107/S1399004714015776
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