4lye
From Proteopedia
(Difference between revisions)
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4lye]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Rhizorhabdus_wittichii_RW1 Rhizorhabdus wittichii RW1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4LYE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4LYE FirstGlance]. <br> | <table><tr><td colspan='2'>[[4lye]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Rhizorhabdus_wittichii_RW1 Rhizorhabdus wittichii RW1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4LYE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4LYE FirstGlance]. <br> | ||
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HPK:(3E)-2,6-DIOXO-6-PHENYLHEX-3-ENOATE'>HPK</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.33Å</td></tr> |
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HPK:(3E)-2,6-DIOXO-6-PHENYLHEX-3-ENOATE'>HPK</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=4lye FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4lye OCA], [https://pdbe.org/4lye PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4lye RCSB], [https://www.ebi.ac.uk/pdbsum/4lye PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4lye ProSAT]</span></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=4lye FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4lye OCA], [https://pdbe.org/4lye PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4lye RCSB], [https://www.ebi.ac.uk/pdbsum/4lye PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4lye ProSAT]</span></td></tr> | ||
</table> | </table> | ||
| - | <div style="background-color:#fffaf0;"> | ||
| - | == Publication Abstract from PubMed == | ||
| - | The meta-cleavage product (MCP) hydrolases utilize a Ser-His-Asp triad to hydrolyze a carbon-carbon bond. Hydrolysis of the MCP substrate has been proposed to proceed via an enol-to-keto tautomerization followed by a nucleophilic mechanism of catalysis. Ketonization involves an intermediate, ESred, possessing a remarkable bathochromically-shifted absorption spectrum. We investigated the catalytic mechanism of the MCP hydrolases using DxnB2 from Sphingomonas wittichii RW1. Pre-steady-state kinetic and LC ESI/MS evaluation of the DxnB2-mediated hydrolysis of 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) to 2-hydroxy-2,4-pentadienoic acid (HPD) and benzoate support a nucleophilic mechanism catalysis. In DxnB2, the rate of ESred decay and product formation showed a solvent kinetic isotope effect of 2.5 indicating that a proton transfer reaction, assigned here to substrate ketonization, limits the rate of acylation. For a series of substituted MCPs, this rate was linearly dependent on MCP pKa2 (betanuc ~1). Structural characterization of DxnB2 S105A:MCP complexes revealed that the catalytic histidine is displaced upon substrate-binding. The results provide evidence for enzyme-catalyzed ketonization in which the catalytic His-Asp pair does not play an essential role. The data further suggest that ESred represents a dianionic intermediate that acts as a general base to activate the serine nucleophile. This substrate-assisted mechanism of nucleophilic catalysis distinguishes MCP hydrolases from other serine hydrolases. | ||
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| - | A substrate-assisted mechanism of nucleophile activation in a Ser-His-Asp containing C-C bond hydrolase.,Ruzzini AC, Bhowmik S, Ghosh S, Yam KC, Bolin JT, Eltis LD Biochemistry. 2013 Sep 25. PMID:24067021<ref>PMID:24067021</ref> | ||
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| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| - | </div> | ||
| - | <div class="pdbe-citations 4lye" style="background-color:#fffaf0;"></div> | ||
| - | == References == | ||
| - | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Current revision
Crystal structure of the S105A mutant of a C-C hydrolase, DxnB2 from Sphingomonas wittichii RW1, in complex with substrate HOPDA
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