1g6a: Difference between revisions
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1g6a]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G6A OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1G6A FirstGlance]. <br> | <table><tr><td colspan='2'>[[1g6a]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G6A OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1G6A FirstGlance]. <br> | ||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>< | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | ||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1g68|1g68]]</td></tr> | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1g68|1g68]]</td></tr> | ||
<tr><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='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><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1g6a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1g6a OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1g6a RCSB], [http://www.ebi.ac.uk/pdbsum/1g6a 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=1g6a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1g6a OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1g6a RCSB], [http://www.ebi.ac.uk/pdbsum/1g6a PDBsum]</span></td></tr> | ||
<table> | </table> | ||
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
[[Image:Consurf_key_small.gif|200px|right]] | [[Image:Consurf_key_small.gif|200px|right]] | ||
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[[Category: Beta-lactamase]] | [[Category: Beta-lactamase]] | ||
[[Category: Pseudomonas aeruginosa]] | [[Category: Pseudomonas aeruginosa]] | ||
[[Category: Castro, L De | [[Category: Castro, L De]] | ||
[[Category: Levesque, R C | [[Category: Levesque, R C]] | ||
[[Category: Lim, D | [[Category: Lim, D]] | ||
[[Category: Passmore, L | [[Category: Passmore, L]] | ||
[[Category: Sanschagrin, F | [[Category: Sanschagrin, F]] | ||
[[Category: Strynadka, N C.J | [[Category: Strynadka, N C.J]] | ||
[[Category: Carbenicillinase]] | [[Category: Carbenicillinase]] | ||
[[Category: Class a beta-lactamase]] | [[Category: Class a beta-lactamase]] | ||
[[Category: Hydrolase]] | [[Category: Hydrolase]] | ||
[[Category: R234k mutant]] | [[Category: R234k mutant]] | ||
Revision as of 03:02, 23 December 2014
PSE-4 CARBENICILLINASE, R234K MUTANTPSE-4 CARBENICILLINASE, R234K MUTANT
Structural highlights
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 PubMedPSE-4 is a class A beta-lactamase produced by strains of Pseudomonas aeruginosa and is highly active for the penicillin derivative carbenicillin. The crystal structure of the wild-type PSE-4 carbenicillinase has been determined to 1.95 A resolution by molecular replacement and represents the first structure of a carbenicillinase published to date. A superposition of the PSE-4 structure with that of TEM-1 shows a rms deviation of 1.3 A for 263 Calpha atoms. Most carbenicillinases are unique among class A beta-lactamases in that residue 234 is an arginine (ABL standard numbering scheme), while in all other class A enzymes this residue is a lysine. Kinetic characterization of a R234K PSE-4 mutant reveals a 50-fold reduction in k(cat)/K(m) and confirms the importance of Arg 234 for carbenicillinase activity. A comparison of the structure of the R234K mutant refined to 1.75 A resolution with the wild-type structure shows that Arg 234 stabilizes an alternate conformation of the Ser 130 side chain, not seen in other class A beta-lactamase structures. Our molecular modeling studies suggest that the position of a bound carbenicillin would be shifted relative to that of a bound benzylpenicillin in order to avoid a steric clash between the carbenicillin alpha-carboxylate group and the conserved side chain of Asn 170. The alternate conformation of the catalytic Ser 130 in wild-type PSE-4 may be involved in accommodating this shift in the bound substrate position. Insights into the molecular basis for the carbenicillinase activity of PSE-4 beta-lactamase from crystallographic and kinetic studies.,Lim D, Sanschagrin F, Passmore L, De Castro L, Levesque RC, Strynadka NC Biochemistry. 2001 Jan 16;40(2):395-402. PMID:11148033[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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