View source for 1xgi


==AmpC beta-lactamase in complex with 3-(3-nitro-phenylsulfamoyl)-thiophene-2-carboxylic acid==
<StructureSection load='1xgi' size='340' side='right'caption='[[1xgi]], [[Resolution|resolution]] 1.96&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1xgi]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XGI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XGI 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]] 1.96&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NST:3-{[(3-NITROANILINE]SULFONYL}THIOPHENE-2-CARBOXYLIC+ACID'>NST</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=1xgi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xgi OCA], [https://pdbe.org/1xgi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xgi RCSB], [https://www.ebi.ac.uk/pdbsum/1xgi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xgi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AMPC_ECOLI AMPC_ECOLI] This protein is a serine beta-lactamase with a substrate specificity for cephalosporins.
== 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/xg/1xgi_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=1xgi ConSurf].
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<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Bacterial expression of beta-lactamases is the most widespread resistance mechanism to beta-lactam antibiotics, such as penicillins and cephalosporins. There is a pressing need for novel, non-beta-lactam inhibitors of these enzymes. One previously discovered novel inhibitor of the beta-lactamase AmpC, compound 1, has several favorable properties: it is chemically dissimilar to beta-lactams and is a noncovalent, competitive inhibitor of the enzyme. However, at 26 microM its activity is modest. Using the X-ray structure of the AmpC/1 complex as a template, 14 analogues were designed and synthesized. The most active of these, compound 10, had a K(i) of 1 microM, 26-fold better than the lead. To understand the origins of this improved activity, the structures of AmpC in complex with compound 10 and an analogue, compound 11, were determined by X-ray crystallography to 1.97 and 1.96 A, respectively. Compound 10 was active in cell culture, reversing resistance to the third generation cephalosporin ceftazidime in bacterial pathogens expressing AmpC. In contrast to beta-lactam-based inhibitors clavulanate and cefoxitin, compound 10 did not up-regulate beta-lactamase expression in cell culture but simply inhibited the enzyme expressed by the resistant bacteria. Its escape from this resistance mechanism derives from its dissimilarity to beta-lactam antibiotics.

Structure-based optimization of a non-beta-lactam lead results in inhibitors that do not up-regulate beta-lactamase expression in cell culture.,Tondi D, Morandi F, Bonnet R, Costi MP, Shoichet BK J Am Chem Soc. 2005 Apr 6;127(13):4632-9. PMID:15796528<ref>PMID:15796528</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1xgi" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Bonnet R]]
[[Category: Costi MP]]
[[Category: Morandi F]]
[[Category: Shoichet BK]]
[[Category: Tondi D]]