View source for 4wvz


==Crystal structure of artificial crosslinked thiol dioxygenase G95C variant from Pseudomonas aeruginosa==
<StructureSection load='4wvz' size='340' side='right'caption='[[4wvz]], [[Resolution|resolution]] 2.09&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4wvz]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_aeruginosa_PAO1 Pseudomonas aeruginosa PAO1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4WVZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4WVZ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.09&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FE2:FE+(II)+ION'>FE2</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=4wvz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4wvz OCA], [https://pdbe.org/4wvz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4wvz RCSB], [https://www.ebi.ac.uk/pdbsum/4wvz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4wvz ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A140UH61_PSEAI A0A140UH61_PSEAI] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Thiol dioxygenases catalyze the synthesis of sulfinic acids in a range of organisms from bacteria to mammals. A thiol dioxygenase from the bacterium Pseudomonas aeruginosa oxidizes both 3-mercaptopropionic acid and cysteine, with a approximately 70 fold preference for 3-mercaptopropionic acid over all pHs. This substrate reactivity is widened compared to other thiol dioxygenases and was exploited in this investigation of the residues important for activity. A simple model incorporating two protonation events was used to fit profiles of the Michaelis-Menten parameters determined at different pH values for both substrates. The pKs determined using plots of kcat/Km differ at low pH, but not in a way easily attributable to protonation of the substrate alone and share a common value at higher pH. Plots of kcat versus pH are also quite different at low pH showing the monoprotonated ES complexes with 3-mercaptopropionic acid and cysteine have different pKs. At higher pH, kcat decreases sigmoidally with a similar pK regardless of substrate. Loss of reactivity at high pH is attributed to deprotonation of tyrosine 159 and its influence on dioxygen binding. A mechanism is proposed by which deprotonation of tyrosine 159 both blocks oxygen binding and concomitantly promotes cystine formation. Finally, the role of tyrosine 159 was further probed by production of a G95C variant that is able to form a cysteine-tyrosine crosslink homologous to that found in mammalian cysteine dioxygenases. Activity of this variant is severely impaired. Crystallography shows that when un-crosslinked, the cysteine thiol excludes tyrosine 159 from its native position, while kinetic analysis shows that the thioether bond impairs reactivity of the crosslinked form.

Substrate and pH-Dependent Kinetic Profile of 3-Mercaptopropionate Dioxygenase from Pseudomonas aeruginosa.,Fellner M, Aloi S, Tchesnokov EP, Wilbanks SM, Jameson GN Biochemistry. 2016 Feb 25. PMID:26878277<ref>PMID:26878277</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4wvz" style="background-color:#fffaf0;"></div>

==See Also==
*[[Dioxygenase 3D structures|Dioxygenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas aeruginosa PAO1]]
[[Category: Fellner M]]
[[Category: Jameson GNL]]
[[Category: Tchesnokov EP]]
[[Category: Wilbanks SM]]