View source for 7ce9


==PQQ-soaked Apo-methanol dehydrogenase (MDH) from Methylococcus capsulatus (Bath)==
<StructureSection load='7ce9' size='340' side='right'caption='[[7ce9]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7ce9]] is a 16 chain structure with sequence from [https://en.wikipedia.org/wiki/Methylococcus_capsulatus_str._Bath Methylococcus capsulatus str. Bath]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7CE9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7CE9 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=PQQ:PYRROLOQUINOLINE+QUINONE'>PQQ</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=7ce9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7ce9 OCA], [https://pdbe.org/7ce9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7ce9 RCSB], [https://www.ebi.ac.uk/pdbsum/7ce9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7ce9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q60AR6_METCA Q60AR6_METCA] 
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== Publication Abstract from PubMed ==
The active site of methanol dehydrogenase (MDH) contains a rare disulfide bridge between adjacent cysteine residues. As a vicinal disulfide, the structure is highly strained, suggesting it might work together with the pyrroloquinoline quinone (PQQ) prosthetic group and the Ca(2+) ion in the catalytic turnover during methanol (CH(3)OH) oxidation. We purify MDH from Methylococcus capsulatus (Bath) with the disulfide bridge broken into two thiols. Spectroscopic and high-resolution X-ray crystallographic studies of this form of MDH indicate that the disulfide bridge is redox active. We observe an internal redox process within the holo-MDH that produces a disulfide radical anion concomitant with a companion PQQ radical, as evidenced by an optical absorption at 408 nm and a magnetically dipolar-coupled biradical in the EPR spectrum. These observations are corroborated by electron-density changes between the two cysteine sulfurs of the disulfide bridge as well as between the bound Ca(2+) ion and the O5-C5 bond of the PQQ in the high-resolution X-ray structure. On the basis of these findings, we propose a mechanism for the controlled redistribution of the two electrons during hydride transfer from the CH(3)OH in the alcohol oxidation without formation of the reduced PQQ ethenediol, a biradical mechanism that allows for possible recovery of the hydride for transfer to an external NAD(+) oxidant in the regeneration of the PQQ cofactor for multiple catalytic turnovers. In support of this mechanism, a steady-state level of the disulfide radical anion is observed during turnover of the MDH in the presence of CH(3)OH and NAD(+).

Mechanism of Pyrroloquinoline Quinone-Dependent Hydride Transfer Chemistry from Spectroscopic and High-Resolution X-ray Structural Studies of the Methanol Dehydrogenase from Methylococcus capsulatus (Bath).,Chan SI, Chuankhayan P, Reddy Nareddy PK, Tsai IK, Tsai YF, Chen KH, Yu SS, Chen CJ J Am Chem Soc. 2021 Mar 10;143(9):3359-3372. doi: 10.1021/jacs.0c11414. Epub 2021 , Feb 25. PMID:33629832<ref>PMID:33629832</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 7ce9" style="background-color:#fffaf0;"></div>

==See Also==
*[[Methanol dehydrogenase|Methanol dehydrogenase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Methylococcus capsulatus str. Bath]]
[[Category: Chan SI]]
[[Category: Chen CJ]]
[[Category: Chen KH-C]]
[[Category: Chuankhayan P]]
[[Category: Nareddy PKR]]
[[Category: Tsai IK]]
[[Category: Tsai YF]]
[[Category: Yu SS-F]]