1HRM

THE PROXIMAL LIGAND VARIANT HIS93TYR OF HORSE HEART MYOGLOBIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å

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


  • 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 sour ...

    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: 
    • Horse Heart Metmyoglobin: A 2.8 Angstroms Resolution Three-Dimensional Structure Determination
      Evans, S.V.,Brayer, G.D.
      (1988) J.Biol.Chem. 263: 4263
    • High-Resolution Study of the Three-Dimensional Structure of Horse Heart Myoglobin
      Evans, S.V.,Brayer, G.D.
      (1990) J.Mol.Biol. 213: 885
    • Crystallization and Preliminary Diffraction Data for Horse Heart Metmyoglobin
      Sherwood, C.,Mauk, A.G.,Brayer, G.D.
      (1987) J.Mol.Biol. 193: 227
    • 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
    • Three-Dimensional Structure of Cyanomet-Sulfmyoglobin C
      Evans, S.V.,Sishta, B.P.,Mauk, A.G.,Brayer, G.D.
      (1994) Proc.Natl.Acad.Sci.USA 91: 4723
    • 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


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MYOGLOBIN
A
153Equus caballusGene Names: MB
Find proteins for P68082 (Equus caballus)
Go to Gene View: MB
Go to UniProtKB:  P68082
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
HEM
Query on HEM

Download SDF File 
Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 65.360α = 90.00
b = 28.900β = 107.06
c = 35.960γ = 90.00
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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