3f2f: Difference between revisions
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[[Image: | ==Crystal structure of the mercury-bound form of MerB, the Organomercurial Lyase involved in a bacterial mercury resistance system== | ||
<StructureSection load='3f2f' size='340' side='right' caption='[[3f2f]], [[Resolution|resolution]] 1.98Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3f2f]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3F2F OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3F2F FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BR:BROMIDE+ION'>BR</scene>, <scene name='pdbligand=HG:MERCURY+(II)+ION'>HG</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1s6l|1s6l]], [[3f0o|3f0o]], [[3f0p|3f0p]], [[3f2g|3f2g]], [[3f2h|3f2h]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">merB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])</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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3f2f FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3f2f OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3f2f RCSB], [http://www.ebi.ac.uk/pdbsum/3f2f PDBsum]</span></td></tr> | |||
</table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/f2/3f2f_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Bacteria resistant to methylmercury utilize two enzymes (MerA and MerB) to degrade methylmercury to the less toxic elemental mercury. The crucial step is the cleavage of the carbon-mercury bond of methylmercury by the organomercurial lyase (MerB). In this study, we determined high resolution crystal structures of MerB in both the free (1.76-A resolution) and mercury-bound (1.64-A resolution) states. The crystal structure of free MerB is very similar to the NMR structure, but important differences are observed when comparing the two structures. In the crystal structure, an amino-terminal alpha-helix that is not present in the NMR structure makes contact with the core region adjacent to the catalytic site. This interaction between the amino-terminal helix and the core serves to bury the active site of MerB. The crystal structures also provide detailed insights into the mechanism of carbon-mercury bond cleavage by MerB. The structures demonstrate that two conserved cysteines (Cys-96 and Cys-159) play a role in substrate binding, carbon-mercury bond cleavage, and controlled product (ionic mercury) release. In addition, the structures establish that an aspartic acid (Asp-99) in the active site plays a crucial role in the proton transfer step required for the cleavage of the carbon-mercury bond. These findings are an important step in understanding the mechanism of carbon-mercury bond cleavage by MerB. | |||
Crystal structures of the organomercurial lyase MerB in its free and mercury-bound forms: insights into the mechanism of methylmercury degradation.,Lafrance-Vanasse J, Lefebvre M, Di Lello P, Sygusch J, Omichinski JG J Biol Chem. 2009 Jan 9;284(2):938-44. Epub 2008 Nov 12. PMID:19004822<ref>PMID:19004822</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
< | |||
[[Category: Alkylmercury lyase]] | [[Category: Alkylmercury lyase]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Lafrance-Vanasse, J | [[Category: Lafrance-Vanasse, J]] | ||
[[Category: Lefebvre, M | [[Category: Lefebvre, M]] | ||
[[Category: Lello, P Di | [[Category: Lello, P Di]] | ||
[[Category: Omichinski, J G | [[Category: Omichinski, J G]] | ||
[[Category: Sygusch, J | [[Category: Sygusch, J]] | ||
[[Category: Lyase]] | [[Category: Lyase]] | ||
[[Category: Merb]] | [[Category: Merb]] | ||
Revision as of 11:40, 26 November 2014
Crystal structure of the mercury-bound form of MerB, the Organomercurial Lyase involved in a bacterial mercury resistance systemCrystal structure of the mercury-bound form of MerB, the Organomercurial Lyase involved in a bacterial mercury resistance system
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBacteria resistant to methylmercury utilize two enzymes (MerA and MerB) to degrade methylmercury to the less toxic elemental mercury. The crucial step is the cleavage of the carbon-mercury bond of methylmercury by the organomercurial lyase (MerB). In this study, we determined high resolution crystal structures of MerB in both the free (1.76-A resolution) and mercury-bound (1.64-A resolution) states. The crystal structure of free MerB is very similar to the NMR structure, but important differences are observed when comparing the two structures. In the crystal structure, an amino-terminal alpha-helix that is not present in the NMR structure makes contact with the core region adjacent to the catalytic site. This interaction between the amino-terminal helix and the core serves to bury the active site of MerB. The crystal structures also provide detailed insights into the mechanism of carbon-mercury bond cleavage by MerB. The structures demonstrate that two conserved cysteines (Cys-96 and Cys-159) play a role in substrate binding, carbon-mercury bond cleavage, and controlled product (ionic mercury) release. In addition, the structures establish that an aspartic acid (Asp-99) in the active site plays a crucial role in the proton transfer step required for the cleavage of the carbon-mercury bond. These findings are an important step in understanding the mechanism of carbon-mercury bond cleavage by MerB. Crystal structures of the organomercurial lyase MerB in its free and mercury-bound forms: insights into the mechanism of methylmercury degradation.,Lafrance-Vanasse J, Lefebvre M, Di Lello P, Sygusch J, Omichinski JG J Biol Chem. 2009 Jan 9;284(2):938-44. Epub 2008 Nov 12. PMID:19004822[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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