7yk9
From Proteopedia
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[7yk9]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Synechocystis_sp._PCC_6803 Synechocystis sp. PCC 6803]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7YK9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7YK9 FirstGlance]. <br> | <table><tr><td colspan='2'>[[7yk9]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Synechocystis_sp._PCC_6803 Synechocystis sp. PCC 6803]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7YK9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7YK9 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></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]] 1.9Å</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></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=7yk9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7yk9 OCA], [https://pdbe.org/7yk9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7yk9 RCSB], [https://www.ebi.ac.uk/pdbsum/7yk9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7yk9 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=7yk9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7yk9 OCA], [https://pdbe.org/7yk9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7yk9 RCSB], [https://www.ebi.ac.uk/pdbsum/7yk9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7yk9 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 I86D Mutant Complexed with Biliverdin at Room Temperature
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