1IX4

Crystal Structure of Rat Heme Oxygenase-1 in complex with Heme bound to Carbon Monoxide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structures of Ferrous and CO-, CN(-)-, and NO-Bound Forms of Rat Heme Oxygenase-1 (HO-1) in Complex with Heme: Structural Implications for Discrimination between CO and O(2) in HO-1.

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

(2003) Biochemistry 42: 9898-9905

  • DOI: 10.1021/bi027268i
  • Primary Citation of Related Structures:  1IX3, 1J02, 1UBB

  • PubMed Abstract: 
  • Heme oxygenase (HO) catalyzes heme degradation by utilizing O(2) and reducing equivalents to produce biliverdin IX alpha, iron, and CO. To avoid product inhibition, the heme[bond]HO complex (heme[bond]HO) is structured to markedly increase its affini ...

    Heme oxygenase (HO) catalyzes heme degradation by utilizing O(2) and reducing equivalents to produce biliverdin IX alpha, iron, and CO. To avoid product inhibition, the heme[bond]HO complex (heme[bond]HO) is structured to markedly increase its affinity for O(2) while suppressing its affinity for CO. We determined the crystal structures of rat ferrous heme[bond]HO and heme[bond]HO bound to CO, CN(-), and NO at 2.3, 1.8, 2.0, and 1.7 A resolution, respectively. The heme pocket of ferrous heme-HO has the same conformation as that of the previously determined ferric form, but no ligand is visible on the distal side of the ferrous heme. Fe[bond]CO and Fe[bond]CN(-) are tilted, whereas the Fe[bond]NO is bent. The structure of heme[bond]HO bound to NO is identical to that bound to N(3)(-), which is also bent as in the case of O(2). Notably, in the CO- and CN(-)-bound forms, the heme and its ligands shift toward the alpha-meso carbon, and the distal F-helix shifts in the opposite direction. These shifts allow CO or CN(-) to bind in a tilted fashion without a collision between the distal ligand and Gly139 O and cause disruption of one salt bridge between the heme and basic residue. The structural identity of the ferrous and ferric states of heme[bond]HO indicates that these shifts are not produced on reduction of heme iron. Neither such conformational changes nor a heme shift occurs on NO or N(3)(-) binding. Heme[bond]HO therefore recognizes CO and O(2) by their binding geometries. The marked reduction in the ratio of affinities of CO to O(2) for heme[bond]HO achieved by an increase in O(2) affinity [Migita, C. T., Matera, K. M., Ikeda-Saito, M., Olson, J. S., Fujii, H., Yoshimura, T., Zhou, H., and Yoshida, T. (1998) J. Biol. Chem. 273, 945-949] is explained by hydrogen bonding and polar interactions that are favorable for O(2) binding, as well as by characteristic structural changes in the CO-bound form.


    Related Citations: 
    • Crystal structure of rat heme oxygenase-1 in complex with heme bound to azide. Implication for regiospecific hydroxylation of heme at the alpha-meso carbon.
      Sugishima, M.,Sakamoto, H.,Higashimoto, Y.,Omata, Y.,Hayashi, S.,Noguchi, M.,Fukuyama, K.
      (2003) J.Biol.Chem. 277: 45086


    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 norvegicusGene 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
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
CMO
Query on CMO

Download SDF File 
Download CCD File 
A
CARBON MONOXIDE
C O
UGFAIRIUMAVXCW-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.195 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 66.000α = 90.00
b = 66.000β = 90.00
c = 120.240γ = 120.00
Software Package:
Software NamePurpose
CNSphasing
CNSrefinement
SCALEPACKdata scaling
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



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