View source for 4h07


==Complex of G65T Myoglobin with Phenol in its Proximal Cavity==
<StructureSection load='4h07' size='340' side='right'caption='[[4h07]], [[Resolution|resolution]] 1.14&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4h07]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Physeter_catodon Physeter catodon]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4H07 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4H07 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]] 1.14&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=IPH:PHENOL'>IPH</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4h07 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4h07 OCA], [https://pdbe.org/4h07 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4h07 RCSB], [https://www.ebi.ac.uk/pdbsum/4h07 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4h07 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MYG_PHYMC MYG_PHYMC] Serves as a reserve supply of oxygen and facilitates the movement of oxygen within muscles.
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== Publication Abstract from PubMed ==
Sperm whale myoglobin (Mb) has weak dehaloperoxidase activity and catalyzes the peroxidative dehalogenation of 2,4,6-trichlorophenol (TCP) to 2,6-dichloroquinone. Crystals of Mb and of its more active G65T variant were used to study the binding of TCP, 4-iodophenol (4-IP) and phenol. The structures of crystals soaked overnight in a 10 mM solution of phenol revealed that a phenol molecule binds in the proximal cavity, forming a hydrogen bond to the hydroxyl of Tyr146 and hydrophobic contacts which include interactions with C(beta) and C(gamma) of the proximal histidine His93. The phenol position corresponds to the strongest xenon binding site, Xe1. It appears that the ligand enters the proximal cavity through a gate formed by the flexible loops 79-86 and 93-103. TCP and 4-IP do not bind to Mb in this manner under similar conditions; however, it appears to be likely that dimethyl sulfoxide (DMSO), which was used at a concentration of 0.8 M to facilitate 4-IP dissolution, binds in the phenol/Xe1 binding site. In this structure, a water molecule coordinated to the heme iron was replaced by an oxygen molecule, reflecting the reduction of the heme. Crystals of Mb and G65T Mb soaked for 5-10 min did not show bound phenol. Kinetic studies of TCP dechlorination showed that phenol has a dual effect: it acts as a competitive inhibitor that is likely to interfere with TCP binding at the heme edge and as a weak activator, likely through binding in the proximal cavity. The lack of phenol bound at the heme edge in the crystal structures suggests that its inhibitory binding only takes place when the heme is activated by hydrogen peroxide.

Complex of myoglobin with phenol bound in a proximal cavity.,Huang X, Wang C, Celeste LR, Lovelace LL, Sun S, Dawson JH, Lebioda L Acta Crystallogr Sect F Struct Biol Cryst Commun. 2012 Dec 1;68(Pt 12):1465-71., doi: 10.1107/S1744309112045514. Epub 2012 Nov 19. PMID:23192025<ref>PMID:23192025</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 4h07" style="background-color:#fffaf0;"></div>

==See Also==
*[[Myoglobin 3D structures|Myoglobin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Physeter catodon]]
[[Category: Celeste LR]]
[[Category: Dawson JH]]
[[Category: Huang X]]
[[Category: Lebioda L]]
[[Category: Lovelace LL]]
[[Category: Shengfang S]]
[[Category: Wang C]]