View source for 1ghi


==STRUCTURE OF BETA-LACTAMASE GLU166ASP:ASN170GLN MUTANT==
<StructureSection load='1ghi' size='340' side='right'caption='[[1ghi]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ghi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GHI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1GHI 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]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO3:CARBONATE+ION'>CO3</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=1ghi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ghi OCA], [https://pdbe.org/1ghi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ghi RCSB], [https://www.ebi.ac.uk/pdbsum/1ghi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ghi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BLAC_STAAU BLAC_STAAU] 
== 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/gh/1ghi_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=1ghi ConSurf].
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== Publication Abstract from PubMed ==
The serine-beta-lactamases hydrolyze beta-lactam antibiotics in a reaction that proceeds via an acyl-enzyme intermediate. The double mutation, E166D:N170Q, of the class A enzyme from Staphylococcus aureus results in a protein incapable of deacylation. The crystal structure of this beta-lactamase, determined at 2.3 A resolution, shows that except for the mutation sites, the structure is very similar to that of the native protein. The crystal structures of two acyl-enzyme adducts, one with benzylpenicillin and the other with cephaloridine, have been determined at 1.76 and 1.86 A resolution, respectively. Both acyl-enzymes show similar key features, with the carbonyl carbon atom of the cleaved beta-lactam bond covalently bound to the side chain of the active site Ser70, and the carbonyl oxygen atom in an oxyanion hole. The thiadolizine ring of the cleaved penicillin is located in a slightly different position than the dihydrothiazine ring of cephaloridine. Consequently, the carboxylate moieties attached to the rings form different sets of interactions. The carboxylate group of benzylpenicillin interacts with the side chain of Gln237. The carboxylate group of cephaloridine is located between Arg244 and Lys234 side chains and also interacts with Ser235 hydroxyl group. The interactions of the cephaloridine resemble those seen in the structure of the acyl-enzyme of beta-lactamase from Escherichia coli with benzylpenicillin. The side chains attached to the cleaved beta-lactam rings of benzylpenicillin and cephaloridine are located in a similar position, which is different than the position observed in the E. coli benzylpenicillin acyl-enzyme complex. The three modes of binding do not show a trend that explains the preference for benzylpenicillin over cephaloridine in the class A beta-lactamases. Rather, the conformational variation arises because cleavage of the beta-lactam bond provides additional flexibility not available when the fused rings are intact. The structural information suggests that specificity is determined prior to the cleavage of the beta-lactam ring, when the rigid fused rings of benzylpenicillin and cephaloridine each form different interactions with the active site.

Structures of the acyl-enzyme complexes of the Staphylococcus aureus beta-lactamase mutant Glu166Asp:Asn170Gln with benzylpenicillin and cephaloridine.,Chen CC, Herzberg O Biochemistry. 2001 Feb 27;40(8):2351-8. PMID:11327855<ref>PMID:11327855</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 1ghi" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-lactamase 3D structures|Beta-lactamase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Staphylococcus aureus]]
[[Category: Chen CCH]]
[[Category: Herzberg O]]