1NZ5

The Horse heart myoglobin variant K45E/K63E complexed with Manganese


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.175 

wwPDB Validation   3D Report Full Report


This is version 1.5 of the entry. See complete history


Literature

Introduction and characterization of a functionally linked metal ion binding site at the exposed heme edge of myoglobin

Hunter, C.L.Maurus, R.Mauk, M.R.Lee, H.Raven, E.L.Tong, H.Nguyen, N.Smith, S.Brayer, G.D.Mauk, A.G.

(2003) Proc Natl Acad Sci U S A 100: 3647-3652

  • DOI: https://doi.org/10.1073/pnas.0636702100
  • Primary Citation of Related Structures:  
    1NZ2, 1NZ3, 1NZ4, 1NZ5

  • PubMed Abstract: 

    A binding site for metal ions has been created on the surface of horse heart myoglobin (Mb) near the heme 6-propionate group by replacing K45 and K63 with glutamyl residues. One-dimensional (1)H NMR spectroscopy indicates that Mn(2+) binds in the vicinity of the heme 6-propionate as anticipated, and potentiometric titrations establish that the affinity of the new site for Mn(2+) is 1.28(4) x 10(4) M(-1) (pH 6.96, ionic strength I = 17.2 microM, 25 degrees C). In addition, these substitutions lower the reduction potential of the protein and increase the pK(a) for the water molecule coordinated to the heme iron of metmyoglobin. The peroxidase [2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid), ABTS, as substrate] and the Mn(2+)-peroxidase activity of the variant are both increased approximately 3-fold. In contrast to wild-type Mb, both the affinity for azide and the midpoint potential of the variant are significantly influenced by the addition of Mn(2+). The structure of the variant has been determined by x-ray crystallography to define the coordination environment of bound Mn(2+) and Cd(2+). Although slight differences are observed between the geometry of the binding of the two metal ions, both are hexacoordinate, and neither involves coordination by E63.


  • Organizational Affiliation

    Department of Biochemistry and Molecular Biology and Protein Engineering Network of Centres of Excellence, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Myoglobin153Equus caballusMutation(s): 2 
Gene Names: MB
UniProt
Find proteins for P68082 (Equus caballus)
Explore P68082 
Go to UniProtKB:  P68082
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP68082
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

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

Download Ideal Coordinates CCD File 
B [auth A]MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.175 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 28.9α = 90
b = 35.6β = 90
c = 125.1γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
PROLSQrefinement
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-04-08
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 1.4: 2021-10-27
    Changes: Database references, Derived calculations
  • Version 1.5: 2024-02-14
    Changes: Data collection