4TYX

Structure of aquoferric sperm whale myoglobin L29H/F33Y/F43H/S92A mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.64 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.156 
  • R-Value Observed: 0.160 

Starting Model: experimental
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This is version 1.5 of the entry. See complete history


Literature

Systematic tuning of heme redox potentials and its effects on O2 reduction rates in a designed oxidase in myoglobin.

Bhagi-Damodaran, A.Petrik, I.D.Marshall, N.M.Robinson, H.Lu, Y.

(2014) J Am Chem Soc 136: 11882-11885

  • DOI: https://doi.org/10.1021/ja5054863
  • Primary Citation of Related Structures:  
    4TYX

  • PubMed Abstract: 

    Cytochrome c Oxidase (CcO) is known to catalyze the reduction of O2 to H2O efficiently with a much lower overpotential than most other O2 reduction catalysts. However, methods by which the enzyme fine-tunes the reduction potential (E°) of its active site and the corresponding influence on the O2 reduction activity are not well understood. In this work, we report systematic tuning of the heme E° in a functional model of CcO in myoglobin containing three histidines and one tyrosine in the distal pocket of heme. By removing hydrogen-bonding interactions between Ser92 and the proximal His ligand and a heme propionate, and increasing hydrophobicity of the heme pocket through Ser92Ala mutation, we have increased the heme E° from 95 ± 2 to 123 ± 3 mV. Additionally, replacing the native heme b in the CcO mimic with heme a analogs, diacetyl, monoformyl, and diformyl hemes, that posses electron-withdrawing groups, resulted in higher E° values of 175 ± 5, 210 ± 6, and 320 ± 10 mV, respectively. Furthermore, O2 consumption studies on these CcO mimics revealed a strong enhancement in O2 reduction rates with increasing heme E°. Such methods of tuning the heme E° through a combination of secondary sphere mutations and heme substitutions can be applied to tune E° of other heme proteins, allowing for comprehensive investigations of the relationship between E° and enzymatic activity.


  • Organizational Affiliation

    Department of Chemistry, University of Illinois, Urbana-Champaign , Urbana, Illinois 61801, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Myoglobin153Physeter catodonMutation(s): 4 
Gene Names: MB
EC: 1.11.1 (UniProt), 1.7 (UniProt)
UniProt
Find proteins for P02185 (Physeter macrocephalus)
Explore P02185 
Go to UniProtKB:  P02185
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02185
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / 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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.64 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.156 
  • R-Value Observed: 0.160 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.467α = 90
b = 47.91β = 90
c = 76.854γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CBASSdata collection
PDB_EXTRACTdata extraction
PHENIXrefinement

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM062211

Revision History  (Full details and data files)

  • Version 1.0: 2014-08-13
    Type: Initial release
  • Version 1.1: 2014-10-29
    Changes: Database references
  • Version 1.2: 2015-02-04
    Changes: Derived calculations
  • Version 1.3: 2017-09-27
    Changes: Advisory, Author supporting evidence, Derived calculations, Other, Source and taxonomy, Structure summary
  • Version 1.4: 2019-12-25
    Changes: Author supporting evidence
  • Version 1.5: 2023-09-27
    Changes: Data collection, Database references, Refinement description