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1ck3

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Revision as of 08:19, 29 November 2017

N276D MUTANT OF ESCHERICHIA COLI TEM-1 BETA-LACTAMASE

Structural highlights

1ck3 is a 1 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Activity:	Beta-lactamase, with EC number 3.5.2.6
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[BLAT_ECOLX] TEM-type are the most prevalent beta-lactamases in enterobacteria; they hydrolyze the beta-lactam bond in susceptible beta-lactam antibiotics, thus conferring resistance to penicillins and cephalosporins. TEM-3 and TEM-4 are capable of hydrolyzing cefotaxime and ceftazidime. TEM-5 is capable of hydrolyzing ceftazidime. TEM-6 is capable of hydrolyzing ceftazidime and aztreonam. TEM-8/CAZ-2, TEM-16/CAZ-7 and TEM-24/CAZ-6 are markedly active against ceftazidime. IRT-4 shows resistance to beta-lactamase inhibitors.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The clinical use of beta-lactam antibiotics combined with beta-lactamase inactivators, such as clavulanate, has resulted in selection of beta-lactamases that are insensitive to inactivation by these molecules. Therefore, therapeutic combinations of an enzyme inactivator and a penicillin are harmless for bacteria harboring such an enzyme. The TEM beta-lactamase variants are the most frequently encountered enzymes of this type, and presently, 20 variants are designated as inhibitor-resistant TEM ("IRT") enzymes. Three mutations appear to account for the phenotype of the majority of IRT enzymes, one of them being the Asn276Asp substitution. In this study, we have characterized the kinetic properties of the inhibition process of the wild-type TEM-1 beta-lactamase and of its Asn276Asp variant with the three clinically used inactivators, clavulanic acid (clavulanate), sulbactam, and tazobactam, and we report the X-ray structure for the mutant variant at 2.3 A resolution. The changes in kinetic parameters for the interactions of the inhibitors with the wild-type and the mutant enzymes were more pronounced for clavulanate, and relatively inconsequential for sulbactam and tazobactam. The structure of the Asn276Asp mutant enzyme revealed a significant movement of Asp276 and the formation of a salt bridge of its side chain with the guanidinium group of Arg244, the counterion of the inhibitor carboxylate. A water molecule critical for the inactivation chemistry by clavulanate, which is observed in the wild-type enzyme structure, is not present in the crystal structure of the mutant variant. Such structural changes favor the turnover process over the inactivation chemistry for clavulanate, with profound phenotypic consequences. The report herein represents the best studied example of inhibitor-resistant beta-lactamases.

X-ray structure of the Asn276Asp variant of the Escherichia coli TEM-1 beta-lactamase: direct observation of electrostatic modulation in resistance to inactivation by clavulanic acid.,Swaren P, Golemi D, Cabantous S, Bulychev A, Maveyraud L, Mobashery S, Samama JP Biochemistry. 1999 Jul 27;38(30):9570-6. PMID:10423234^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Swaren P, Golemi D, Cabantous S, Bulychev A, Maveyraud L, Mobashery S, Samama JP. X-ray structure of the Asn276Asp variant of the Escherichia coli TEM-1 beta-lactamase: direct observation of electrostatic modulation in resistance to inactivation by clavulanic acid. Biochemistry. 1999 Jul 27;38(30):9570-6. PMID:10423234 doi:10.1021/bi990758z

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1ck3"

@@ Line 1: / Line 1: @@
 ==N276D MUTANT OF ESCHERICHIA COLI TEM-1 BETA-LACTAMASE==
 <StructureSection load='1ck3' size='340' side='right' caption='[[1ck3]], [[Resolution|resolution]] 2.28&Aring;' scene=''>
@@ Line 4: / Line 5: @@
 <table><tr><td colspan='2'>[[1ck3]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CK3 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1CK3 FirstGlance]. <br>
 </td></tr><tr id='activity'><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 id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ck3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ck3 OCA], [http://pdbe.org/1ck3 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ck3 RCSB], [http://www.ebi.ac.uk/pdbsum/1ck3 PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ck3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ck3 OCA], [http://pdbe.org/1ck3 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1ck3 RCSB], [http://www.ebi.ac.uk/pdbsum/1ck3 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1ck3 ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 27: / Line 28: @@
 </div>
 <div class="pdbe-citations 1ck3" style="background-color:#fffaf0;"></div>
-==See Also==
-*[[Beta-lactamase|Beta-lactamase]]
 == References ==
 <references/>

1ck3

From Proteopedia

Revision as of 08:19, 29 November 2017

N276D MUTANT OF ESCHERICHIA COLI TEM-1 BETA-LACTAMASE

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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