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| | ==Crystal structure of a MerB-trimethytin complex.== | | ==Crystal structure of a MerB-trimethytin complex.== |
| - | <StructureSection load='5u83' size='340' side='right' caption='[[5u83]], [[Resolution|resolution]] 1.61Å' scene=''> | + | <StructureSection load='5u83' size='340' side='right'caption='[[5u83]], [[Resolution|resolution]] 1.61Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5u83]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5U83 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5U83 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5u83]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5U83 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5U83 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=BR:BROMIDE+ION'>BR</scene>, <scene name='pdbligand=ZN8:TRIMETHYLTIN+CHLORIDE'>ZN8</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.609Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3f0p|3f0p]], [[5c0u|5c0u]], [[5c17|5c17]], [[5c0t|5c0t]], [[5u79|5u79]], [[5u7a|5u7a]], [[5u7b|5u7b]], [[5u7c|5u7c]], [[5u82|5u82]], [[5u88|5u88]]</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=BR:BROMIDE+ION'>BR</scene>, <scene name='pdbligand=ZN8:TRIMETHYLTIN+CHLORIDE'>ZN8</scene></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Alkylmercury_lyase Alkylmercury lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.99.1.2 4.99.1.2] </span></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=5u83 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5u83 OCA], [https://pdbe.org/5u83 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5u83 RCSB], [https://www.ebi.ac.uk/pdbsum/5u83 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5u83 ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5u83 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5u83 OCA], [http://pdbe.org/5u83 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5u83 RCSB], [http://www.ebi.ac.uk/pdbsum/5u83 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5u83 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/MERB_ECOLX MERB_ECOLX]] Cleaves the carbon-mercury bond of organomercurials such as phenylmercuric acetate. One product is Hg(2+), which is subsequently detoxified by the mercuric reductase (By similarity). | + | [https://www.uniprot.org/uniprot/MERB_ECOLX MERB_ECOLX] Cleaves the carbon-mercury bond of organomercurials such as phenylmercuric acetate. One product is Hg(2+), which is subsequently detoxified by the mercuric reductase (By similarity). |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Alkylmercury lyase]] | |
| - | [[Category: Mansour, A]] | |
| - | [[Category: Omichinski, J G]] | |
| - | [[Category: Stevenson, M]] | |
| - | [[Category: Sygusch, J]] | |
| - | [[Category: Wahba, H M]] | |
| - | [[Category: Wilcox, D E]] | |
| - | [[Category: Bacterial protein]] | |
| - | [[Category: Cysteine]] | |
| | [[Category: Escherichia coli]] | | [[Category: Escherichia coli]] |
| - | [[Category: Lyase]] | + | [[Category: Large Structures]] |
| - | [[Category: Mercury]] | + | [[Category: Mansour A]] |
| - | [[Category: Metal binding protein]] | + | [[Category: Omichinski JG]] |
| - | [[Category: Trimethyltin]] | + | [[Category: Stevenson M]] |
| | + | [[Category: Sygusch J]] |
| | + | [[Category: Wahba HM]] |
| | + | [[Category: Wilcox DE]] |
| Structural highlights
Function
MERB_ECOLX Cleaves the carbon-mercury bond of organomercurials such as phenylmercuric acetate. One product is Hg(2+), which is subsequently detoxified by the mercuric reductase (By similarity).
Publication Abstract from PubMed
The organomercurial lyase MerB has the unique ability to cleave carbon-Hg bonds, and structural studies indicate that three residues in the active site (C96, D99, and C159 in E. coli MerB) play important roles in the carbon-Hg bond cleavage. However, the role of each residue in carbon-metal bond cleavage has not been well-defined. To do so, we have structurally and biophysically characterized the interaction of MerB with a series of organotin and organolead compounds. Studies with two known inhibitors of MerB, dimethyltin (DMT) and triethyltin (TET), reveal that they inhibit by different mechanisms. In both cases the initial binding is to D99, but DMT subsequently binds to C96, which induces a conformation change in the active site. In contrast, diethyltin (DET) is a substrate for MerB and the SnIV product remains bound in the active site in a coordination similar to that of HgII following cleavage of organomercurial compounds. The results with analogous organolead compounds are similar in that trimethyllead (TML) is not cleaved and binds only to D99, whereas diethyllead (DEL) is a substrate and the PbIV product remains bound in the active site. Binding and cleavage is an exothermic reaction, while binding to D99 has negligible net heat flow. These results show that initial binding of organometallic compounds to MerB occurs at D99 followed, in some cases, by cleavage and loss of the organic moieties and binding of the metal ion product to C96, D99, and C159. The N-terminus of MerA is able to extract the bound PbVI but not the bound SnIV. These results suggest that MerB could be utilized for bioremediation applications, but certain organolead and organotin compounds may present an obstacle by inhibiting the enzyme.
Structural and Biochemical Characterization of Organotin and Organolead Compounds Binding to the Organomercurial Lyase MerB Provide New Insights into Its Mechanism of Carbon-Metal Bond Cleavage.,Wahba HM, Stevenson MJ, Mansour A, Sygusch J, Wilcox DE, Omichinski JG J Am Chem Soc. 2017 Jan 3. doi: 10.1021/jacs.6b11327. PMID:27989130[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wahba HM, Stevenson MJ, Mansour A, Sygusch J, Wilcox DE, Omichinski JG. Structural and Biochemical Characterization of Organotin and Organolead Compounds Binding to the Organomercurial Lyase MerB Provide New Insights into Its Mechanism of Carbon-Metal Bond Cleavage. J Am Chem Soc. 2017 Jan 3. doi: 10.1021/jacs.6b11327. PMID:27989130 doi:http://dx.doi.org/10.1021/jacs.6b11327
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