3hgx: Difference between revisions
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< | ==Crystal Structure of Pseudomonas aeruginosa Isochorismate-Pyruvate Lyase K42A mutant in complex with salicylate and pyruvate== | ||
<StructureSection load='3hgx' size='340' side='right'caption='[[3hgx]], [[Resolution|resolution]] 2.50Å' scene=''> | |||
You may | == Structural highlights == | ||
<table><tr><td colspan='2'>[[3hgx]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3HGX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3HGX FirstGlance]. <br> | |||
or | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5Å</td></tr> | ||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PYR:PYRUVIC+ACID'>PYR</scene>, <scene name='pdbligand=SAL:2-HYDROXYBENZOIC+ACID'>SAL</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=3hgx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3hgx OCA], [https://pdbe.org/3hgx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3hgx RCSB], [https://www.ebi.ac.uk/pdbsum/3hgx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3hgx ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/PCHB_PSEAE PCHB_PSEAE] Has isochorismate-pyruvate lyase activity. Probably involved in the conversion of isochorismate to salicylate and pyruvate. | |||
== 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/hg/3hgx_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=3hgx ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The isochorismate-pyruvate lyase from Pseudomonas aeruginosa (PchB) catalyzes two pericyclic reactions in a single active site. PchB physiologically produces salicylate and pyruvate from isochorismate for ultimate incorporation of the salicylate into the siderophore pyochelin. PchB also produces prephenate from chorismate, most likely due to structural homology to the Escherchia coli chorismate mutase. The molecular basis of catalysis among enzymatic pericyclic reactions is a matter of debate, one view holding that catalysis may be derived from electrostatic transition state stabilization and the opposing view that catalysis is derived from the generation of a reactive substrate conformation. Mutant forms of PchB were generated by site-directed mutagenesis at the site (K42) hypothesized to be key for electrostatic transition state stabilization (K42A, K42Q, K42E, and K42H). The loop containing K42 is mobile, and a mutant to slow loop dynamics was also designed (A43P). Finally, a previously characterized mutation (I87T) was also produced. Circular dichroism was used to assess the overall effect on secondary structure as a result of the mutations, and X-ray crystallographic structures are reported for K42A with salicylate and pyruvate bound and for apo-I87T. The data illustrate that the active site architecture is maintained in K42A-PchB, which indicates that differences in activity are not caused by secondary structural changes or by differences in active site loop conformation but rather by the chemical nature of this key residue. In contrast, the I87T structure demonstrates considerable mobility, suggesting that loop dynamics and conformational plasticity may be important for efficient catalysis. Finally, the mutational effects on k(cat) provide evidence that the two activities of PchB are not covariant and that a single hypothesis may not provide a sufficient explanation for catalysis. | |||
Structure-function analyses of isochorismate-pyruvate lyase from Pseudomonas aeruginosa suggest differing catalytic mechanisms for the two pericyclic reactions of this bifunctional enzyme.,Luo Q, Olucha J, Lamb AL Biochemistry. 2009 Jun 16;48(23):5239-45. PMID:19432488<ref>PMID:19432488</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3hgx" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Isochorismate pyruvate lyase|Isochorismate pyruvate lyase]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | [[Category: Large Structures]] | ||
== | |||
< | |||
[[Category: Pseudomonas aeruginosa]] | [[Category: Pseudomonas aeruginosa]] | ||
[[Category: Lamb | [[Category: Lamb AL]] | ||
[[Category: Luo | [[Category: Luo Q]] | ||
Latest revision as of 10:21, 6 September 2023
Crystal Structure of Pseudomonas aeruginosa Isochorismate-Pyruvate Lyase K42A mutant in complex with salicylate and pyruvateCrystal Structure of Pseudomonas aeruginosa Isochorismate-Pyruvate Lyase K42A mutant in complex with salicylate and pyruvate
Structural highlights
FunctionPCHB_PSEAE Has isochorismate-pyruvate lyase activity. Probably involved in the conversion of isochorismate to salicylate and pyruvate. 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 PubMedThe isochorismate-pyruvate lyase from Pseudomonas aeruginosa (PchB) catalyzes two pericyclic reactions in a single active site. PchB physiologically produces salicylate and pyruvate from isochorismate for ultimate incorporation of the salicylate into the siderophore pyochelin. PchB also produces prephenate from chorismate, most likely due to structural homology to the Escherchia coli chorismate mutase. The molecular basis of catalysis among enzymatic pericyclic reactions is a matter of debate, one view holding that catalysis may be derived from electrostatic transition state stabilization and the opposing view that catalysis is derived from the generation of a reactive substrate conformation. Mutant forms of PchB were generated by site-directed mutagenesis at the site (K42) hypothesized to be key for electrostatic transition state stabilization (K42A, K42Q, K42E, and K42H). The loop containing K42 is mobile, and a mutant to slow loop dynamics was also designed (A43P). Finally, a previously characterized mutation (I87T) was also produced. Circular dichroism was used to assess the overall effect on secondary structure as a result of the mutations, and X-ray crystallographic structures are reported for K42A with salicylate and pyruvate bound and for apo-I87T. The data illustrate that the active site architecture is maintained in K42A-PchB, which indicates that differences in activity are not caused by secondary structural changes or by differences in active site loop conformation but rather by the chemical nature of this key residue. In contrast, the I87T structure demonstrates considerable mobility, suggesting that loop dynamics and conformational plasticity may be important for efficient catalysis. Finally, the mutational effects on k(cat) provide evidence that the two activities of PchB are not covariant and that a single hypothesis may not provide a sufficient explanation for catalysis. Structure-function analyses of isochorismate-pyruvate lyase from Pseudomonas aeruginosa suggest differing catalytic mechanisms for the two pericyclic reactions of this bifunctional enzyme.,Luo Q, Olucha J, Lamb AL Biochemistry. 2009 Jun 16;48(23):5239-45. PMID:19432488[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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