View source for 6vk4


==Crystal Structure of Methylosinus trichosporium OB3b Soluble Methane Monooxygenase Hydroxylase and Regulatory Component Complex==
<StructureSection load='6vk4' size='340' side='right'caption='[[6vk4]], [[Resolution|resolution]] 2.35&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6vk4]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Methylosinus_trichosporium_OB3b Methylosinus trichosporium OB3b]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6VK4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6VK4 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]] 2.35&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BEZ:BENZOIC+ACID'>BEZ</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene>, <scene name='pdbligand=FE2:FE+(II)+ION'>FE2</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=6vk4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6vk4 OCA], [https://pdbe.org/6vk4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6vk4 RCSB], [https://www.ebi.ac.uk/pdbsum/6vk4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6vk4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MEMA_METTR MEMA_METTR] Responsible for the initial oxygenation of methane to methanol in methanotrophs. It also catalyzes the monohydroxylation of a variety of unactivated alkenes, alicyclic, aromatic and heterocyclic compounds.
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== Publication Abstract from PubMed ==
The metalloenzyme soluble methane monooxygenase (sMMO) consists of hydroxylase (sMMOH), regulatory (MMOB), and reductase components. When sMMOH forms a complex with MMOB, the rate constants are greatly increased for the sequential access of O2, protons, and CH4 to an oxygen-bridged diferrous metal cluster located in the buried active site. Here, we report high-resolution X-ray crystal structures of the diferric and diferrous states of both sMMOH and the sMMOH:MMOB complex using the components from Methylosinus trichosporium OB3b. These structures are analyzed for O2 access routes enhanced when the complex forms. Previously reported, lower-resolution structures of the sMMOH:MMOB complex from the sMMO of Methylococcus capsulatus Bath revealed a series of cavities through sMMOH postulated to serve as the O2 conduit. This potential role is evaluated in greater detail using the current structures. Additionally, a search for other potential O2 conduits in the M. trichosporium OB3b sMMOH:MMOB complex revealed a narrow molecular tunnel, termed the W308-tunnel. This tunnel is sized appropriately for O2 and traverses the sMMOH-MMOB interface before accessing the active site. The kinetics of reaction of O2 with the diferrous sMMOH:MMOB complex in solution show that use of the MMOB V41R variant decreases the rate constant for O2 binding &gt;25000-fold without altering the component affinity. The location of Val41 near the entrance to the W308-tunnel is consistent with the tunnel serving as the primary route for the transfer of O2 into the active site. Accordingly, the crystal structures show that formation of the diferrous sMMOH:MMOB complex restricts access through the chain of cavities while opening the W308-tunnel.

Structural Studies of the Methylosinus trichosporium OB3b Soluble Methane Monooxygenase Hydroxylase and Regulatory Component Complex Reveal a Transient Substrate Tunnel.,Jones JC, Banerjee R, Shi K, Aihara H, Lipscomb JD Biochemistry. 2020 Aug 18;59(32):2946-2961. doi: 10.1021/acs.biochem.0c00459., Epub 2020 Jul 30. PMID:32692178<ref>PMID:32692178</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 6vk4" style="background-color:#fffaf0;"></div>

==See Also==
*[[Methane monooxygenase 3D structures|Methane monooxygenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Methylosinus trichosporium OB3b]]
[[Category: Aihara H]]
[[Category: Banerjee R]]
[[Category: Jones JC]]
[[Category: Lipscomb JD]]
[[Category: Shi K]]