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==The 1.48 Angstrom crystal structure of evolved galactose oxidase variant A3.E7==
<StructureSection load='6xlt' size='340' side='right'caption='[[6xlt]], [[Resolution|resolution]] 1.48&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6XLT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6XLT 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]] 1.478&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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=6xlt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6xlt OCA], [https://pdbe.org/6xlt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6xlt RCSB], [https://www.ebi.ac.uk/pdbsum/6xlt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6xlt ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Galactose oxidase (GAO) contains a Cu(II)-ligand radical cofactor. The cofactor, which is autocatalytically generated through the oxidation of the copper, consists of a cysteine-tyrosine radical (Cys-Tyr(*)) as a copper ligand. The formation of the cross-linked thioether bond is accompanied by a C-H bond scission on Tyr272 with few details known thus far. Here, we report the genetic incorporation of 3,5-dichlorotyrosine (Cl2-Tyr) and 3,5-difluorotyrosine (F2-Tyr) to replace Tyr272 in the GAO(V) previously optimized for expression through directed evolution. The proteins with an unnatural tyrosine residue are catalytically competent. We determined the high-resolution crystal structures of the GAO(V), Cl2-Tyr272, and F2-Tyr272 incorporated variants at 1.48, 1.23, and 1.80 A resolution, respectively. The structural data showed only one halogen remained in the cofactor, indicating that an oxidative carbon-chlorine/fluorine bond scission has occurred during the autocatalytic process of cofactor biogenesis. Using hydroxyurea as a radical scavenger, the spin-coupled hidden Cu(II) was observed by EPR spectroscopy. Thus, the structurally defined catalytic center with genetic unnatural tyrosine substitution is in the radical containing form as in the wild-type, i.e., Cu(II)-(Cl-Tyr(*)-Cys) or Cu(II)-(F-Tyr(*)-Cys). These findings illustrate a previously unobserved C-F/C-Cl bond cleavage in biology mediated by a mononuclear copper center.

Formation of Monofluorinated Radical Cofactor in Galactose Oxidase through Copper-Mediated C-F Bond Scission.,Li J, Davis I, Griffith WP, Liu A J Am Chem Soc. 2020 Nov 4;142(44):18753-18757. doi: 10.1021/jacs.0c08992. Epub, 2020 Oct 22. PMID:33091303<ref>PMID:33091303</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Galactose oxidase|Galactose oxidase]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Li J]]
[[Category: Liu A]]