6p8l: Difference between revisions
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==Escherichia coli Bacterioferritin Substituted with Zinc Protoporphyrin IX (Zn Absorption Edge X-ray Data)== | ==Escherichia coli Bacterioferritin Substituted with Zinc Protoporphyrin IX (Zn Absorption Edge X-ray Data)== | ||
<StructureSection load='6p8l' size='340' side='right'caption='[[6p8l]]' scene=''> | <StructureSection load='6p8l' size='340' side='right'caption='[[6p8l]], [[Resolution|resolution]] 2.10Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6P8L OCA]. For a <b>guided tour on the structure components</b> use [ | <table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6P8L OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6P8L FirstGlance]. <br> | ||
</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.1Å</td></tr> | ||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MLI:MALONATE+ION'>MLI</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene>, <scene name='pdbligand=ZNH:PROTOPORPHYRIN+IX+CONTAINING+ZN'>ZNH</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=6p8l FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6p8l OCA], [https://pdbe.org/6p8l PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6p8l RCSB], [https://www.ebi.ac.uk/pdbsum/6p8l PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6p8l ProSAT]</span></td></tr> | |||
</table> | </table> | ||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The iron storage protein bacterioferritin (Bfr) binds up to 12 hemes b at specific sites in its protein shell. The heme b can be substituted with the photosensitizer Zn(II)-protoporphyrin IX (ZnPP), and photosensitized reductive iron release from the ferric oxyhydroxide {[FeO(OH)]n} core inside the ZnPP-Bfr protein shell was demonstrated [Cioloboc, D., et al. (2018) Biomacromolecules 19, 178-187]. This report describes the X-ray crystal structure of ZnPP-Bfr and the effects of loaded iron on the photophysical properties of the ZnPP. The crystal structure of ZnPP-Bfr shows a unique six-coordinate zinc in the ZnPP with two axial methionine sulfur ligands. Steady state and transient ultraviolet-visible absorption and luminescence spectroscopies show that irradiation with light overlapping the Soret absorption causes oxidation of ZnPP to the cation radical ZnPP(*+) only when the ZnPP-Bfr is loaded with [FeO(OH)]n. Femtosecond transient absorption spectroscopy shows that this photooxidation occurs from the singlet excited state ((1)ZnPP*) on the picosecond time scale and is consistent with two oxidizing populations of Fe(3+), which do not appear to involve the ferroxidase center iron. We propose that [FeO(OH)]n clusters at or near the inner surface of the protein shell are responsible for ZnPP photooxidation. Hopping of the photoinjected electrons through the [FeO(OH)]n would effectively cause migration of Fe(2+) through the inner cavity to pores where it exits the protein. Reductive iron mobilization is presumed to be a physiological function of Bfrs. The phototriggered Fe(3+) reduction could be used to identify the sites of iron mobilization within the Bfr protein shell. | |||
Structure of a Zinc Porphyrin-Substituted Bacterioferritin and Photophysical Properties of Iron Reduction.,Benavides BS, Valandro S, Cioloboc D, Taylor AB, Schanze KS, Kurtz DM Jr Biochemistry. 2020 Apr 28;59(16):1618-1629. doi: 10.1021/acs.biochem.9b01103., Epub 2020 Apr 16. PMID:32283930<ref>PMID:32283930</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 6p8l" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Ferritin 3D structures|Ferritin 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
