View source for 5ala


==Structure of Leishmania major peroxidase D211R mutant (low res)==
<StructureSection load='5ala' size='340' side='right'caption='[[5ala]], [[Resolution|resolution]] 2.73&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ala]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Leishmania_major Leishmania major]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5ALA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5ALA 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]] 2.73&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</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=5ala FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ala OCA], [https://pdbe.org/5ala PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ala RCSB], [https://www.ebi.ac.uk/pdbsum/5ala PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ala ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q4Q3K2_LEIMA Q4Q3K2_LEIMA] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Leishmania major peroxidase (LmP) is very similar to the well-known yeast cytochrome c peroxidase (CcP). Both enzymes catalyze the peroxidation of cytochrome c. Like CcP, LmP reacts with H2O2 to form Compound I, which consists of a ferryl heme and a Trp radical, FeIV horizontal lineO;Trp*+. Cytochrome c (Cytc) reduces the Trp radical to give Compound II, FeIV horizontal lineO;Trp, which is followed by an intramolecular electron transfer to give FeIII-OH;Trp*+, and in the last step, Cytc reduces the Trp radical. In this study, we have used steady-state and single-turnover kinetics to improve our understanding of the overall mechanism of LmP catalysis. While the activity of CcP greatly increases with ionic strength, the kcat for LmP remains relatively constant at all ionic strengths tested. Therefore, unlike CcP, where dissociation of oxidized Cytc is limiting at low ionic strengths, association/dissociation reactions are not limiting at any ionic strength in LmP. We conclude that in LmP, the intramolecular electron transfer reaction, FeIV horizontal lineO;Trp to FeIII-OH;Trp*+, is limiting at all ionic strengths. Unlike CcP, LmP depends on key intermolecular ion pairs to form the electron transfer competent complex. Mutating these sites causes the initial rate of association to decrease by 2 orders of magnitude and a substantial decrease in kcat. The drop in kcat is due to a switch in the rate-limiting step of the mutants from intramolecular electron transfer to the rate of association in forming the LmP-LmCytc complex. These studies show that while LmP and CcP form very similar complexes and exhibit similar activities, they substantially differ in how their activity changes as a function of ionic strength. This difference is primarily due to the heavy reliance of LmP on highly specific intermolecular ion pairs, while CcP relies mainly on nonpolar interactions.

Enzymatic Mechanism of Leishmania major Peroxidase and the Critical Role of Specific Ionic Interactions.,Chreifi G, Hollingsworth SA, Li H, Tripathi S, Arce AP, Magana-Garcia HI, Poulos TL Biochemistry. 2015 May 19. PMID:25941976<ref>PMID:25941976</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 5ala" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ascorbate peroxidase 3D structures|Ascorbate peroxidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Leishmania major]]
[[Category: Arce AP]]
[[Category: Chreifi G]]
[[Category: Hollingsworth SA]]
[[Category: Li H]]
[[Category: Magana-Garcia HI]]
[[Category: Poulos TL]]
[[Category: Tripathi S]]