Biological Assembly 1  

 3D View: Structure | Ligand Interaction

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Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 17599.87 
• Atom Count: 1242 
• Residue Count: 153 
• Unique protein chains: 1

1NZ3

K45E-K63E Variant of Horse Heart Myoglobin

• DOI: 10.2210/pdb1NZ3/pdb

• Classification: OXYGEN STORAGE/TRANSPORT
• Organism(s): Equus caballus
• Expression System: Escherichia coli
• Mutation(s): 2 


• Deposited: 2003-02-15 Released: 2003-04-08 
• Deposition Author(s): 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.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.6 Å

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.USA 100: 3647-3652

• PubMed: 12644706 
• DOI: 10.1073/pnas.0636702100
• Primary Citation of Related Structures:  
  1NZ5, 1NZ4, 1NZ2


• 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.

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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: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Myoglobin	A	153	Equus caballus	Mutation(s): 2  Gene Names: MB
Find proteins for P68082 (Equus caballus) Go to Gene View: MB Go to UniProtKB:  P68082

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
HEM	A	PROTOPORPHYRIN IX CONTAINING FE HEME C34 H32 Fe N4 O4 KABFMIBPWCXCRK-RGGAHWMASA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.6 Å
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length (Å)	Angle (°)
a = 29.000	α = 90.00
b = 35.800	β = 90.00
c = 125.800	γ = 90.00

Software Package:

Software Name	Purpose
X-PLOR	model building
PROLSQ	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2003-02-15 
• Released Date: 2003-04-08 
• Deposition Author(s): 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.

Revision History 

• Version 1.0: 2003-04-08
  Type: Initial release
• Version 1.1: 2008-04-29
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance
• Version 1.3: 2017-10-11
  Type: Refinement description