1HRM

THE PROXIMAL LIGAND VARIANT HIS93TYR OF HORSE HEART MYOGLOBIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.151 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The proximal ligand variant His93Tyr of horse heart myoglobin.

Hildebrand, D.P.Burk, D.L.Maurus, R.Ferrer, J.C.Brayer, G.D.Mauk, A.G.

(1995) Biochemistry 34: 1997-2005

  • DOI: 10.1021/bi00006a021
  • Primary Citation of Related Structures:  
    1HRM

  • PubMed Abstract: 
  • The spectroscopic and structural properties of the His93Tyr variant of horse heart myoglobin have been studied to assess the effects of replacing the proximal His residue of this protein with a tyrosyl residue as occurs in catalases from various sources. The variant in the ferric form exhibits electronic spectra that are independent of pH between pH 7 and 10, and it exhibits changes in absorption maxima and intensity that are consistent with a five-coordinate heme iron center at the active site ...

    The spectroscopic and structural properties of the His93Tyr variant of horse heart myoglobin have been studied to assess the effects of replacing the proximal His residue of this protein with a tyrosyl residue as occurs in catalases from various sources. The variant in the ferric form exhibits electronic spectra that are independent of pH between pH 7 and 10, and it exhibits changes in absorption maxima and intensity that are consistent with a five-coordinate heme iron center at the active site. The EPR spectrum of the variant is that of a high-spin, rhombic system similar to that reported for bovine liver catalase. The 1D 1H-NMR spectrum of the variant confirms the five-coordinate nature of the heme iron center and exhibits a broad resonance at 112.5 ppm that is attributable to the meta protons of the phenolate ligand. This result indicates that the new Tyr ligand flips at a significant rate in this protein. The thermal stability of the Fe(III) derivative is unchanged from that of the wild-type protein (pH 8) while the midpoint reduction potential [-208 mV vs SHE (pH 8.0, 25 degrees C)] is about 250 mV lower. The three-dimensional structure of the variant determined by X-ray diffraction analysis confirms the five-coordinate nature of the heme iron center and establishes that the introduction of a proximal Tyr ligand is accommodated by a shift of the F helix (residues 88-99) in which this residue resides away from the heme pocket. Additional effects of this change are small shifts in the positions of Leu29, a heme propionate, and a heme vinyl group that are accompanied by altered hydrogen bonding interactions with the heme prosthetic group.(ABSTRACT TRUNCATED AT 250 WORDS)


    Related Citations: 
    • Structural Characterization of Heme Ligation in the His64-->Tyr Variant of Myoglobin
      Maurus, R., Bogumil, R., Luo, Y., Tang, H.L., Smith, M., Mauk, A.G., Brayer, G.D.
      (1994) J Biol Chem 269: 12606
    • Ftir Analysis of the Interaction of Azide with Horse Heart Myoglobin
      Bogumil, R., Hunter, C.L., Maurus, R., Tang, H.L., Lee, H., Lloyd, E., Brayer, G.D., Smith, M., Mauk, A.G.
      (1994) Biochemistry 33: 7600
    • Three-Dimensional Structure of Cyanomet-Sulfmyoglobin C
      Evans, S.V., Sishta, B.P., Mauk, A.G., Brayer, G.D.
      (1994) Proc Natl Acad Sci U S A 91: 4723
    • High-Resolution Study of the Three-Dimensional Structure of Horse Heart Myoglobin
      Evans, S.V., Brayer, G.D.
      (1990) J Mol Biol 213: 885
    • Horse Heart Metmyoglobin: A 2.8 Angstroms Resolution Three-Dimensional Structure Determination
      Evans, S.V., Brayer, G.D.
      (1988) J Biol Chem 263: 4263
    • Crystallization and Preliminary Diffraction Data for Horse Heart Metmyoglobin
      Sherwood, C., Mauk, A.G., Brayer, G.D.
      (1987) J Mol Biol 193: 227

    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MYOGLOBIN A153Equus caballusMutation(s): 0 
Gene Names: MB
Find proteins for P68082 (Equus caballus)
Explore P68082 
Go to UniProtKB:  P68082
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download Ideal Coordinates CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
SO4
Query on SO4

Download Ideal Coordinates CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.151 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 65.36α = 90
b = 28.9β = 107.06
c = 35.96γ = 90
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1995-01-26
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance