3jyi

From Proteopedia

(Difference between revisions)

Revision as of 10:14, 4 August 2016

Structural and biochemical evidence that a TEM-1 {beta}-lactamase Asn170Gly active site mutant acts via substrate-assisted catalysis

Structural highlights

3jyi is a 6 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.
Ligands:	,
Related:	1btl, 1fqg
Gene:	bla, blaT-3, blaT-4, blaT-5, blaT-6, TEM-1 ("Bacillus coli" Migula 1895)
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.

Publication Abstract from PubMed

TEM-1 beta-lactamase is the most common plasmid-encoded beta-lactamase in Gram-negative bacteria and is a model class A enzyme. The active site of class A beta-lactamases share several conserved residues including Ser(70), Glu(166), and Asn(170) that coordinate a hydrolytic water involved in deacylation. Unlike Ser(70) and Glu(166), the functional significance of residue Asn(170) is not well understood even though it forms hydrogen bonds with both Glu(166) and the hydrolytic water. The goal of this study was to examine the importance of Asn(170) for catalysis and substrate specificity of beta-lactam antibiotic hydrolysis. The codon for position 170 was randomized to create a library containing all 20 possible amino acids. The random library was introduced into Escherichia coli, and functional clones were selected on agar plates containing ampicillin. DNA sequencing of the functional clones revealed that only asparagine (wild type) and glycine at this position are consistent with wild-type function. The determination of kinetic parameters for several substrates revealed that the N170G mutant is very efficient at hydrolyzing substrates that contain a primary amine in the antibiotic R-group that would be close to the Asn(170) side chain in the acyl-intermediate. In addition, the x-ray structure of the N170G enzyme indicated that the position of an active site water important for deacylation is altered compared with the wild-type enzyme. Taken together, the results suggest the N170G TEM-1 enzyme hydrolyzes ampicillin efficiently because of substrate-assisted catalysis where the primary amine of the ampicillin R-group positions the hydrolytic water and allows for efficient deacylation.

Structural and biochemical evidence that a TEM-1 beta-lactamase N170G active site mutant acts via substrate-assisted catalysis.,Brown NG, Shanker S, Prasad BV, Palzkill T J Biol Chem. 2009 Nov 27;284(48):33703-12. Epub 2009 Oct 6. PMID:19812041^[1]

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

References

↑ Brown NG, Shanker S, Prasad BV, Palzkill T. Structural and biochemical evidence that a TEM-1 beta-lactamase N170G active site mutant acts via substrate-assisted catalysis. J Biol Chem. 2009 Nov 27;284(48):33703-12. Epub 2009 Oct 6. PMID:19812041 doi:10.1074/jbc.M109.053819

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/3jyi"

@@ Line 1: / Line 1: @@
 ==Structural and biochemical evidence that a TEM-1 {beta}-lactamase Asn170Gly active site mutant acts via substrate-assisted catalysis==
 <StructureSection load='3jyi' size='340' side='right' caption='[[3jyi]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[3jyi]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3JYI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3JYI FirstGlance]. <br>
+<table><tr><td colspan='2'>[[3jyi]] is a 6 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=3JYI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3JYI FirstGlance]. <br>
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EPE:4-(2-HYDROXYETHYL)-1-PIPERAZINE+ETHANESULFONIC+ACID'>EPE</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr>
 <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1btl|1btl]], [[1fqg|1fqg]]</td></tr>
-<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">bla, blaT-3, blaT-4, blaT-5, blaT-6, TEM-1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])</td></tr>
+<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">bla, blaT-3, blaT-4, blaT-5, blaT-6, TEM-1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</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=3jyi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3jyi OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3jyi RCSB], [http://www.ebi.ac.uk/pdbsum/3jyi 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=3jyi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3jyi OCA], [http://pdbe.org/3jyi PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3jyi RCSB], [http://www.ebi.ac.uk/pdbsum/3jyi PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3jyi ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 19: / Line 20: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 3jyi" style="background-color:#fffaf0;"></div>
 ==See Also==
@@ Line 26: / Line 28: @@
 __TOC__
 </StructureSection>
+[[Category: Bacillus coli migula 1895]]
 [[Category: Beta-lactamase]]
-[[Category: Escherichia coli]]
 [[Category: Brown, N G]]
 [[Category: Palzkill, T G]]

3jyi

From Proteopedia

Revision as of 10:14, 4 August 2016

Structural and biochemical evidence that a TEM-1 {beta}-lactamase Asn170Gly active site mutant acts via substrate-assisted catalysis

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox