4whp: Difference between revisions
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==Resting Protocatechuate 3,4-dioxygenase (pseudomonas putida) at pH 6.5== | ==Resting Protocatechuate 3,4-dioxygenase (pseudomonas putida) at pH 6.5== | ||
<StructureSection load='4whp' size='340' side='right' caption='[[4whp]], [[Resolution|resolution]] 1.54Å' scene=''> | <StructureSection load='4whp' size='340' side='right' caption='[[4whp]], [[Resolution|resolution]] 1.54Å' scene=''> | ||
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<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4who|4who]], [[4whq|4whq]], [[4whr|4whr]], [[4whs|4whs]]</td></tr> | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4who|4who]], [[4whq|4whq]], [[4whr|4whr]], [[4whs|4whs]]</td></tr> | ||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Protocatechuate_3,4-dioxygenase Protocatechuate 3,4-dioxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.13.11.3 1.13.11.3] </span></td></tr> | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Protocatechuate_3,4-dioxygenase Protocatechuate 3,4-dioxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.13.11.3 1.13.11.3] </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=4whp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4whp OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4whp RCSB], [http://www.ebi.ac.uk/pdbsum/4whp 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=4whp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4whp OCA], [http://pdbe.org/4whp PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4whp RCSB], [http://www.ebi.ac.uk/pdbsum/4whp PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4whp ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | </div> | ||
<div class="pdbe-citations 4whp" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Dioxygenase|Dioxygenase]] | |||
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 23:48, 11 August 2016
Resting Protocatechuate 3,4-dioxygenase (pseudomonas putida) at pH 6.5Resting Protocatechuate 3,4-dioxygenase (pseudomonas putida) at pH 6.5
Structural highlights
Function[PCXA_PSEPU] Plays an essential role in the utilization of numerous aromatic and hydroaromatic compounds via the beta-ketoadipate pathway. [PCXB_PSEPU] Plays an essential role in the utilization of numerous aromatic and hydroaromatic compounds via the beta-ketoadipate pathway. Publication Abstract from PubMedIntradiol aromatic ring-cleaving dioxygenases use an active site, nonheme Fe3+ to activate O2 and catecholic substrates for reaction. The inability of Fe3+ to directly bind O2 presents a mechanistic conundrum. The reaction mechanism of protocatechuate 3,4-dioxygenase is investigated here using the alternative substrate 4-fluorocatechol. This substrate is found to slow the reaction at several steps throughout the mechanistic cycle, allowing the intermediates to be detected in solution studies. When the reaction was initiated in an enzyme crystal, it was found to halt at one of two intermediates depending on the pH of the surrounding solution. The X-ray crystal structure of the intermediate at pH 6.5 revealed the key alkylperoxo-Fe3+ species, and the anhydride-Fe3+ intermediate was found for a crystal reacted at pH 8.5. Intermediates of these types have not been structurally characterized for intradiol dioxygenases, and they validate four decades of spectroscopic, kinetic, and computational studies. In contrast to our similar in crystallo crystallographic studies of an Fe2+-containing extradiol dioxygenase, no evidence for a superoxo or peroxo intermediate preceding the alkylperoxo was found. This observation and the lack of spectroscopic evidence for an Fe2+ intermediate that could bind O2 are consistent with concerted formation of the alkylperoxo followed by Criegee rearrangement to yield the anhydride and ultimately ring-opened product. Structural comparison of the alkylperoxo intermediates from the intra- and extradiol dioxygenases provides a rationale for site specificity of ring cleavage. Crystal structures of alkylperoxo and anhydride intermediates in an intradiol ring-cleaving dioxygenase.,Knoot CJ, Purpero VM, Lipscomb JD Proc Natl Acad Sci U S A. 2014 Dec 29. pii: 201419118. PMID:25548185[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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