5AL9

Structure of Leishmania major peroxidase D211R mutant (high res)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.37 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.186 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Enzymatic Mechanism of Leishmania major Peroxidase and the Critical Role of Specific Ionic Interactions.

Chreifi, G.Hollingsworth, S.A.Li, H.Tripathi, S.Arce, A.P.Magana-Garcia, H.I.Poulos, T.L.

(2015) Biochemistry 54: 3328-3336

  • DOI: 10.1021/acs.biochem.5b00338
  • Primary Citation of Related Structures:  
    5AL9, 5ALA

  • PubMed Abstract: 
  • 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, Fe(IV)═O;Trp(•+) ...

    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, Fe(IV)═O;Trp(•+). Cytochrome c (Cytc) reduces the Trp radical to give Compound II, Fe(IV)═O;Trp, which is followed by an intramolecular electron transfer to give Fe(III)-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, Fe(IV)═O;Trp to Fe(III)-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.


    Organizational Affiliation

    †Department of Molecular Biology and Biochemistry, ‡Department of Chemistry, and §Department of Pharmaceutical Sciences, University of California, Irvine, California 92697-3900, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ASCORBATE PEROXIDASEA270Leishmania majorMutation(s): 1 
Gene Names: APXLMJF_34_0070
EC: 1.11.1.5 (PDB Primary Data), 1.11.1.11 (UniProt)
Find proteins for Q4Q3K2 (Leishmania major)
Explore Q4Q3K2 
Go to UniProtKB:  Q4Q3K2
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download Ideal Coordinates CCD File 
B [auth A]PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
CA
Query on CA

Download Ideal Coordinates CCD File 
C [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
K
Query on K

Download Ideal Coordinates CCD File 
D [auth A]POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.37 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.186 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 142.439α = 90
b = 57.86β = 97.59
c = 36.62γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
iMOSFLMdata reduction
SCALAdata scaling
PHENIXphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-05-20
    Type: Initial release
  • Version 1.1: 2015-06-17
    Changes: Database references
  • Version 1.2: 2019-10-09
    Changes: Data collection, Database references, Other