1znb
From Proteopedia
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- | [[ | + | ==METALLO-BETA-LACTAMASE== |
+ | <StructureSection load='1znb' size='340' side='right' caption='[[1znb]], [[Resolution|resolution]] 1.85Å' scene=''> | ||
+ | == Structural highlights == | ||
+ | <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> | ||
+ | </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> | ||
+ | <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> | ||
+ | <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> | ||
+ | <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> | ||
+ | <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/zn/1znb_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 == | ||
+ | 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. | ||
- | + | 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> | |
- | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
- | + | </div> | |
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==See Also== | ==See Also== | ||
*[[Beta-lactamase|Beta-lactamase]] | *[[Beta-lactamase|Beta-lactamase]] | ||
- | + | == References == | |
- | == | + | <references/> |
- | < | + | __TOC__ |
+ | </StructureSection> | ||
[[Category: Bacteroides fragilis]] | [[Category: Bacteroides fragilis]] | ||
[[Category: Beta-lactamase]] | [[Category: Beta-lactamase]] |
Revision as of 03:20, 29 September 2014
METALLO-BETA-LACTAMASE
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