1J2C

Crystal structure of rat heme oxygenase-1 in complex with biliverdin IXalpha-iron cluster

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.194 

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This is version 1.2 of the entry. See complete history. 

Literature

Crystal Structure of Rat Heme Oxygenase-1 in Complex with Biliverdin-Iron Chelate: CONFORMATIONAL CHANGE OF THE DISTAL HELIX DURING THE HEME CLEAVAGE REACTION.

Sugishima, M., Sakamoto, H., Higashimoto, Y., Noguchi, M., Fukuyama, K.

(2003) J.Biol.Chem. 278: 32352-32358

  • DOI: 10.1074/jbc.M303682200

  • PubMed Abstract: 

    • The crystal structure of rat heme oxygenase-1 in complex with biliverdin-iron chelate (biliverdin(Fe)-HO-1), the immediate precursor of the final product, biliverdin, has been determined at a 2.4-A resolution. The electron density in the heme pocket ...

    The crystal structure of rat heme oxygenase-1 in complex with biliverdin-iron chelate (biliverdin(Fe)-HO-1), the immediate precursor of the final product, biliverdin, has been determined at a 2.4-A resolution. The electron density in the heme pocket clearly showed that the tetrapyrrole ring of heme is cleaved at the alpha-meso edge. Like the heme bound to HO-1, biliverdin-iron chelate is located between the distal and proximal helices, but its accommodation state seems to be less stable in light of the disordering of the solvent-exposed propionate and vinyl groups. The middle of the distal helix is shifted away from the center of the active site in biliverdin(Fe)-HO-1, increasing the size of the heme pocket. The hydrogen-bonding interaction between Glu-29 and Gln-38, considered to restrain the orientation of the proximal helix in the heme-HO-1 complex, was lost in biliverdin(Fe)-HO-1, leading to relaxation of the helix. Biliverdin has a distorted helical conformation; the lactam oxygen atom of its pyrrole ring-A interacted with Asp-140 through a hydrogen-bonding solvent network. Because of the absence of a distal water ligand, the iron atom is five-coordinated with His-25 and four pyrrole nitrogen atoms. The coordination geometry deviates considerably from a square pyramid, suggesting that the iron may be readily dissociated. We speculate that the opened conformation of the heme pocket facilitates sequential product release, first iron then biliverdin, and that because of biliverdin's increased flexibility, iron release triggers its slow dissociation.

    Organizational Affiliation: 

    Department of Biology, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Heme Oxygenase-1
A
267Rattus norvegicusMutation(s): 0 
Gene Names: Hmox1
EC: 1.14.14.18
Find proteins for P06762 (Rattus norvegicus)
Go to UniProtKB:  P06762
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FE
Query on FE
Download SDF File 
Download CCD File 
A
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
BLA
Query on BLA
Download SDF File 
Download CCD File 
A
BILIVERDINE IX ALPHA
C33 H34 N4 O6
GWZYPXHJIZCRAJ-SRVCBVSDSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.194 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 65.400α = 90.00
b = 65.400β = 90.00
c = 121.300γ = 120.00
Software Package:
Software NamePurpose
SCALAdata scaling
CNSrefinement
CCP4data scaling
CNSphasing
MOSFLMdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-09-02
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance