7ykb
From Proteopedia
(Difference between revisions)
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[7ykb]] 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=7YKB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7YKB FirstGlance]. <br> | <table><tr><td colspan='2'>[[7ykb]] 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=7YKB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7YKB FirstGlance]. <br> | ||
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BLR:3-[5-[(Z)-(4-ethenyl-3-methyl-5-oxidanylidene-pyrrol-2-ylidene)methyl]-2-[[5-[(Z)-(3-ethenyl-4-methyl-5-oxidanylidene-pyrrol-2-ylidene)methyl]-3-(3-hydroxy-3-oxopropyl)-4-methyl-1H-pyrrol-2-yl]methyl]-4-methyl-1H-pyrrol-3-yl]propanoic+acid'>BLR</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Hybrid , Neutron Diffraction , X-ray diffraction, [[Resolution|Resolution]] 1.38Å</td></tr> |
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BLR:3-[5-[(Z)-(4-ethenyl-3-methyl-5-oxidanylidene-pyrrol-2-ylidene)methyl]-2-[[5-[(Z)-(3-ethenyl-4-methyl-5-oxidanylidene-pyrrol-2-ylidene)methyl]-3-(3-hydroxy-3-oxopropyl)-4-methyl-1H-pyrrol-2-yl]methyl]-4-methyl-1H-pyrrol-3-yl]propanoic+acid'>BLR</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></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=7ykb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7ykb OCA], [https://pdbe.org/7ykb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7ykb RCSB], [https://www.ebi.ac.uk/pdbsum/7ykb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7ykb 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=7ykb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7ykb OCA], [https://pdbe.org/7ykb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7ykb RCSB], [https://www.ebi.ac.uk/pdbsum/7ykb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7ykb ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
[https://www.uniprot.org/uniprot/PCYA_SYNY3 PCYA_SYNY3] Catalyzes the four-electron reduction of biliverdin IX-alpha (2-electron reduction at both the A and D rings); the reaction proceeds via an isolatable 2-electron intermediate, 181,182-dihydrobiliverdin (By similarity). | [https://www.uniprot.org/uniprot/PCYA_SYNY3 PCYA_SYNY3] Catalyzes the four-electron reduction of biliverdin IX-alpha (2-electron reduction at both the A and D rings); the reaction proceeds via an isolatable 2-electron intermediate, 181,182-dihydrobiliverdin (By similarity). | ||
| - | <div style="background-color:#fffaf0;"> | ||
| - | == Publication Abstract from PubMed == | ||
| - | PcyA, a ferredoxin-dependent bilin pigment reductase, catalyzes the site-specific reduction of the two vinyl groups of biliverdin (BV), producing phycocyanobilin. Previous neutron crystallography detected both the neutral BV and its protonated form (BVH(+)) in the wildtype (WT) PcyA-BV complex, and a nearby catalytic residue Asp105 was found to have two conformations (protonated and deprotonated). Semiempirical calculations have suggested that the protonation states of BV are reflected in the absorption spectrum of the WT PcyA-BV complex. In the previously determined absorption spectra of the PcyA D105N and I86D mutants, complexed with BV, a peak at 730 nm, observed in the WT, disappeared and increased, respectively. Here, we performed neutron crystallography and quantum chemical analysis of the D105N-BV and I86D-BV complexes to determine the protonation states of BV and the surrounding residues and study the correlation between the absorption spectra and protonation states around BV. Neutron structures elucidated that BV in the D105N mutant is in a neutral state, whereas that in the I86D mutant is dominantly in a protonated state. Glu76 and His88 showed different hydrogen bonding with surrounding residues compared with WT PcyA, further explaining why D105N and I86D have much lower activities for phycocyanobilin synthesis than the WT PcyA. Our quantum mechanics/molecular mechanics calculations of the absorption spectra showed that the spectral change in D105N arises from Glu76 deprotonation, consistent with the neutron structure. Collectively, our findings reveal more mechanistic details of bilin pigment biosynthesis. | ||
| - | + | ==See Also== | |
| - | + | *[[Phycocyanobilin:ferredoxin oxidoreductase|Phycocyanobilin:ferredoxin oxidoreductase]] | |
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__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Current revision
Neutron Structure of PcyA D105N Mutant Complexed with Biliverdin at Room Temperature
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