View source for 6rr4


==Structure of 25% reduced KpDyP==
<StructureSection load='6rr4' size='340' side='right'caption='[[6rr4]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6RR4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6RR4 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=6rr4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6rr4 OCA], [https://pdbe.org/6rr4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6rr4 RCSB], [https://www.ebi.ac.uk/pdbsum/6rr4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6rr4 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Since the advent of protein crystallography, atomic-level macromolecular structures have provided a basis to understand biological function. Enzymologists use detailed structural insights on ligand coordination, interatomic distances and positioning of catalytic amino acids to rationalize the underlying electronic reaction mechanisms. Often the proteins in question catalyze redox reactions using metal cofactors that are explicitly intertwined with their function. In these cases, the exact nature of the coordination sphere and the oxidation state of the metal is of utmost importance. Unfortunately, the redox active nature of metal cofactors makes them especially susceptible to photoreduction, meaning that information obtained by photoreducing X-ray sources about the environment of the cofactor are the least trustworthy part of the structure. In this work we directly compare the kinetics of photoreduction of six different heme protein crystal species at by X-ray radiation. We show that a dose of approximately 40 kGy already yields 50% ferrous iron in a heme protein crystal. We also demonstrate that the kinetics of photoreduction are completely independent from variables unique to the different samples tested. The photoreduction-induced structural rearrangements around the metal cofactors have to be considered when biochemical data of ferric proteins are rationalized by constraints derived from crystal structures of reduced enzymes.

X-ray induced photoreduction of heme metal centers rapidly induces active site perturbations in a protein-independent manner.,Pfanzagl V, Beale JH, Michlits H, Schmidt D, Gabler T, Obinger C, Djinovic-Carugo K, Hofbauer S J Biol Chem. 2020 Jul 28. pii: RA120.014087. doi: 10.1074/jbc.RA120.014087. PMID:32723869<ref>PMID:32723869</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6rr4" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Beale J]]
[[Category: Hofbauer S]]
[[Category: Pfanzagl V]]