1znb

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[[Image:1znb.png|left|200px]]
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==METALLO-BETA-LACTAMASE==
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<StructureSection load='1znb' size='340' side='right' caption='[[1znb]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
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== Structural highlights ==
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<table><tr><td colspan='2'>[[1znb]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Bacteroides_fragilis Bacteroides fragilis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZNB OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ZNB FirstGlance]. <br>
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</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene><br>
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<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CCRA3 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=817 Bacteroides fragilis])</td></tr>
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<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Beta-lactamase Beta-lactamase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.6 3.5.2.6] </span></td></tr>
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<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1znb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1znb OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1znb RCSB], [http://www.ebi.ac.uk/pdbsum/1znb PDBsum]</span></td></tr>
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<table>
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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/zn/1znb_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</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].
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<div style="clear:both"></div>
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<div style="background-color:#fffaf0;">
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== Publication Abstract from PubMed ==
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BACKGROUND: The metallo-beta-lactamase from Bacteroides fragilis hydrolyzes a wide range of beta-lactam antibiotics, and is not clinically susceptible to any known beta-lactamase inhibitors. B. fragilis is associated with post-surgery hospital infections, and there has been a recent report of plasmid-mediated dissemination of the enzyme. Effective inhibitors are therefore urgently needed. Knowledge of the three-dimensional structure will aid in the drug design effort. RESULTS: The crystal structure of the enzyme has been determined by using multiwavelength anomalous diffraction at the zinc absorption edge and refined to 1.85 A resolution. The structure is a four-layer alpha/beta/beta/alpha molecule. The active site, found at the edge of the beta sandwich contains a binuclear zinc center with several novel features. One zinc is tetrahedrally coordinated, the other has a trigonal bipyramidal coordination; a water/hydroxide molecule serves as a ligand for both metals. The residues that coordinate the two zincs are invariant in all metallo-beta-lactamases that have been sequenced, except for two conservative replacements. Despite the existence of the pattern for binuclear zinc binding, the reported structure of the Bacillus cereus enzyme contains only a single zinc. CONCLUSIONS: Structural analysis indicates that affinity for the penta-coordinated zinc can be modulated by neighboring residues, perhaps explaining the absence of the second zinc in the B. cereus structure. Models of bound substrates suggest that the active-site channel can accommodate a wide variety of beta-lactams. We propose that the zinc cluster prepares an hydroxide, probably the hydroxide that ligates both zincs, for nucleophilic attack on the carbonyl carbon atom of the beta-lactam. The resulting negatively charged tetrahedral intermediate implicated in catalysis is stabilized by an oxyanion hole formed by the side chain of the invariant Asn 193 and the tetrahedral zinc.
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{{STRUCTURE_1znb| PDB=1znb | SCENE= }}
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Crystal structure of the wide-spectrum binuclear zinc beta-lactamase from Bacteroides fragilis.,Concha NO, Rasmussen BA, Bush K, Herzberg O Structure. 1996 Jul 15;4(7):823-36. PMID:8805566<ref>PMID:8805566</ref>
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===METALLO-BETA-LACTAMASE===
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From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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</div>
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{{ABSTRACT_PUBMED_8805566}}
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==About this Structure==
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[[1znb]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Bacteroides_fragilis Bacteroides fragilis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZNB OCA].
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==See Also==
==See Also==
*[[Beta-lactamase|Beta-lactamase]]
*[[Beta-lactamase|Beta-lactamase]]
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== References ==
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==Reference==
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<references/>
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<ref group="xtra">PMID:008805566</ref><references group="xtra"/>
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__TOC__
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</StructureSection>
[[Category: Bacteroides fragilis]]
[[Category: Bacteroides fragilis]]
[[Category: Beta-lactamase]]
[[Category: Beta-lactamase]]

Revision as of 03:20, 29 September 2014

METALLO-BETA-LACTAMASE

1znb, resolution 1.85Å

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