View source for 1sml


==METALLO BETA LACTAMASE L1 FROM STENOTROPHOMONAS MALTOPHILIA==
<StructureSection load='1sml' size='340' side='right'caption='[[1sml]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1sml]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Stenotrophomonas_maltophilia Stenotrophomonas maltophilia]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SML OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1SML 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]] 1.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=1sml FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1sml OCA], [https://pdbe.org/1sml PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1sml RCSB], [https://www.ebi.ac.uk/pdbsum/1sml PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1sml ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BLA1_STEMA BLA1_STEMA] Has a high activity against imipenem.
== 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/sm/1sml_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1sml ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The structure of the L1 metallo-beta-lactamase from the opportunistic pathogen Stenotrophomonas maltophilia has been determined at 1.7 A resolution by the multiwavelength anomalous dispersion (MAD) approach exploiting both the intrinsic binuclear zinc centre and incorporated selenomethionine residues. L1 is unique amongst all known beta-lactamases in that it exists as a tetramer. The protein exhibits the alphabeta/betaalpha fold found only in the metallo-beta-lactamases and displays several unique features not previously observed in these enzymes. These include a disulphide bridge and two substantially elongated loops connected to the active site of the enzyme. Two closely spaced zinc ions are bound at the active site with tetrahedral (Zn1) and trigonal bipyramidal (Zn2) co-ordination, respectively; these are bridged by a water molecule which we propose acts as the nucleophile in the hydrolytic reaction. Ligation of the second zinc ion involves both residues and geometry which have not been previously observed in the metallo-beta-lactamases. Simulated binding of the substrates ampicillin, ceftazidime and imipenem suggests that the substrate is able to bind to the enzyme in a variety of different conformations whose common features are direct interactions of the beta-lactam carbonyl oxygen and nitrogen with the zinc ions and of the beta-lactam carboxylate with Ser187. We describe a catalytic mechanism whose principal features are a nucleophilic attack of the bridging water on the beta-lactam carbonyl carbon, electrostatic stabilisation of a negatively charged tetrahedral transition state and protonation of the beta-lactam nitrogen by a second water molecule co-ordinated by Zn2. Further, we propose that direct metal:substrate interactions provide a substantial contribution to substrate binding and that this may explain the lack of specificity which is a feature of this class of enzyme.

The crystal structure of the L1 metallo-beta-lactamase from Stenotrophomonas maltophilia at 1.7 A resolution.,Ullah JH, Walsh TR, Taylor IA, Emery DC, Verma CS, Gamblin SJ, Spencer J J Mol Biol. 1998 Nov 20;284(1):125-36. PMID:9811546<ref>PMID:9811546</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1sml" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Stenotrophomonas maltophilia]]
[[Category: Emery DC]]
[[Category: Gamblin SJ]]
[[Category: Spencer J]]
[[Category: Taylor IA]]
[[Category: Ullah JH]]
[[Category: Verma CS]]
[[Category: Walsh TR]]