View source for 3znb


==METALLO-BETA-LACTAMASE (ZN, HG-BOUND FORM)==
<StructureSection load='3znb' size='340' side='right'caption='[[3znb]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3znb]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacteroides_fragilis Bacteroides fragilis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3ZNB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3ZNB 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HG:MERCURY+(II)+ION'>HG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=3znb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3znb OCA], [https://pdbe.org/3znb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3znb RCSB], [https://www.ebi.ac.uk/pdbsum/3znb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3znb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BLAB_BACFG BLAB_BACFG] Can hydrolyze carbapenem compounds.
== 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/3znb_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/main_output.php?pdb_ID=3znb ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The metallo-beta-lactamases require zinc or cadmium for hydrolyzing beta-lactam antibiotics and are inhibited by mercurial compounds. To data, there are no clinically useful inhibitors of this class of enzymes. The crystal structure of the Zn(2+)-bound enzyme from Bacteroides fragilis contains a binuclear zinc center in the active site. A hydroxide, coordinated to both zinc atoms, is proposed as the moiety that mounts the nucleophilic attack on the carbonyl carbon atom of the beta-lactam ring. To study the metal coordination further, the crystal structures of a Cd(2+)-bound enzyme and of an Hg(2+)-soaked zinc-containing enzyme have been determined at 2.1 A and 2.7 A, respectively. Given the diffraction resolution, the Cd(2+)-bound enzyme exhibits the same active-site architecture as that of the Zn(2+)-bound enzyme, consistent with the fact that both forms are enzymatically active. The 10-fold reduction in activity of the Cd(2+)-bound molecule compared with the Zn(2+)-bound enzyme is attributed to fine differences in the charge distribution due to the difference in the ionic radii of the two metals. In contrast, in the Hg(2+)-bound structure, one of the zinc ions, Zn2, was ejected, and the other zinc ion, Zn1, remained in the same site as in the 2-Zn(2+)-bound structure. Instead of the ejected zinc, a mercury ion binds between Cys 104 and Cys 181, 4.8 A away from Zn1 and 3.9 A away from the site where Zn2 is located in the 2-Zn(2+)-bound molecule. The perturbed binuclear metal cluster explains the inactivation of the enzyme by mercury compounds.

Crystal structures of the cadmium- and mercury-substituted metallo-beta-lactamase from Bacteroides fragilis.,Concha NO, Rasmussen BA, Bush K, Herzberg O Protein Sci. 1997 Dec;6(12):2671-6. PMID:9416622<ref>PMID:9416622</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3znb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacteroides fragilis]]
[[Category: Large Structures]]
[[Category: Concha NO]]
[[Category: Herzberg O]]