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[[ | ==Structure of the Isochorismate-Pyruvate Lyase from Pseudomonas aerugionsa with Bound Salicylate and Pyruvate== | ||
<StructureSection load='3rem' size='340' side='right' caption='[[3rem]], [[Resolution|resolution]] 1.95Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3rem]] is a 2 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=3REM OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3REM FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=PYR:PYRUVIC+ACID'>PYR</scene>, <scene name='pdbligand=SAL:2-HYDROXYBENZOIC+ACID'>SAL</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">PA4230, pchB ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=287 Pseudomonas aeruginosa])</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=3rem FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3rem OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3rem RCSB], [http://www.ebi.ac.uk/pdbsum/3rem PDBsum]</span></td></tr> | |||
<table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
An isochorismate-pyruvate lyase with adventitious chorismate mutase activity from Pseudomonas aerugionsa (PchB) achieves catalysis of both pericyclic reactions in part by the stabilization of reactive conformations and in part by electrostatic transition-state stabilization. When the active site loop Lys42 is mutated to histidine, the enzyme develops a pH dependence corresponding to a loss of catalytic power upon deprotonation of the histidine. Structural data indicate that the change is not due to changes in active site architecture, but due to the difference in charge at this key site. With loss of the positive charge on the K42H side chain at high pH, the enzyme retains lyase activity at approximately 100-fold lowered catalytic efficiency but loses detectable mutase activity. We propose that both substrate organization and electrostatic transition state stabilization contribute to catalysis. However, the dominant reaction path for catalysis is dependent on reaction conditions, which influence the electrostatic properties of the enzyme active site amino acid side chains. | |||
pH Dependence of Catalysis by Pseudomonas aeruginosa Isochorismate-Pyruvate Lyase: Implications for Transition State Stabilization and the Role of Lysine 42.,Olucha J, Ouellette AN, Luo Q, Lamb AL Biochemistry. 2011 Jul 22. PMID:21751784<ref>PMID:21751784</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
< | |||
[[Category: Pseudomonas aeruginosa]] | [[Category: Pseudomonas aeruginosa]] | ||
[[Category: Lamb, A L.]] | [[Category: Lamb, A L.]] | ||
Revision as of 07:51, 5 June 2014
Structure of the Isochorismate-Pyruvate Lyase from Pseudomonas aerugionsa with Bound Salicylate and PyruvateStructure of the Isochorismate-Pyruvate Lyase from Pseudomonas aerugionsa with Bound Salicylate and Pyruvate
Structural highlights
Publication Abstract from PubMedAn isochorismate-pyruvate lyase with adventitious chorismate mutase activity from Pseudomonas aerugionsa (PchB) achieves catalysis of both pericyclic reactions in part by the stabilization of reactive conformations and in part by electrostatic transition-state stabilization. When the active site loop Lys42 is mutated to histidine, the enzyme develops a pH dependence corresponding to a loss of catalytic power upon deprotonation of the histidine. Structural data indicate that the change is not due to changes in active site architecture, but due to the difference in charge at this key site. With loss of the positive charge on the K42H side chain at high pH, the enzyme retains lyase activity at approximately 100-fold lowered catalytic efficiency but loses detectable mutase activity. We propose that both substrate organization and electrostatic transition state stabilization contribute to catalysis. However, the dominant reaction path for catalysis is dependent on reaction conditions, which influence the electrostatic properties of the enzyme active site amino acid side chains. pH Dependence of Catalysis by Pseudomonas aeruginosa Isochorismate-Pyruvate Lyase: Implications for Transition State Stabilization and the Role of Lysine 42.,Olucha J, Ouellette AN, Luo Q, Lamb AL Biochemistry. 2011 Jul 22. PMID:21751784[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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