Structural highlights
Function
[HMOX1_RAT] Heme oxygenase cleaves the heme ring at the alpha methene bridge to form biliverdin. Biliverdin is subsequently converted to bilirubin by biliverdin reductase. Under physiological conditions, the activity of heme oxygenase is highest in the spleen, where senescent erythrocytes are sequestrated and destroyed.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
HO (haem oxygenase) catalyses the degradation of haem to biliverdin, CO and ferrous iron via three successive oxygenation reactions, i.e. haem to alpha-hydroxyhaem, alpha-hydroxyhaem to alpha-verdohaem and alpha-verdohaem to ferric biliverdin-iron chelate. In the present study, we determined the crystal structure of ferrous alpha-verdohaem-rat HO-1 complex at 2.2 A (1 A=0.1 nm) resolution. The overall structure of the verdohaem complex was similar to that of the haem complex. Water or OH- was co-ordinated to the verdohaem iron as a distal ligand. A hydrogen-bond network consisting of water molecules and several amino acid residues was observed at the distal side of verdohaem. Such a hydrogen-bond network was conserved in the structures of rat HO-1 complexes with haem and with the ferric biliverdin-iron chelate. This hydrogen-bond network may act as a proton donor to form an activated oxygen intermediate, probably a ferric hydroperoxide species, in the degradation of alpha-verdohaem to ferric biliverdin-iron chelate similar to that seen in the first oxygenation step.
Crystal structure of rat haem oxygenase-1 in complex with ferrous verdohaem: presence of a hydrogen-bond network on the distal side.,Sato H, Sugishima M, Sakamoto H, Higashimoto Y, Shimokawa C, Fukuyama K, Palmer G, Noguchi M Biochem J. 2009 Apr 15;419(2):339-45. PMID:19154182[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Sato H, Sugishima M, Sakamoto H, Higashimoto Y, Shimokawa C, Fukuyama K, Palmer G, Noguchi M. Crystal structure of rat haem oxygenase-1 in complex with ferrous verdohaem: presence of a hydrogen-bond network on the distal side. Biochem J. 2009 Apr 15;419(2):339-45. PMID:19154182 doi:10.1042/BJ20082279
