1IVJ
Crystal Structure of Rat Hemeoxygenase-1 in Complex with Heme and Azide.
Summary for 1IVJ
| Entry DOI | 10.2210/pdb1ivj/pdb |
| Related | 1DVE 1IRM |
| Descriptor | Hemeoxygenase-1, AZIDE ION, PROTOPORPHYRIN IX CONTAINING FE, ... (4 entities in total) |
| Functional Keywords | alpha helix, di-oxygen analog complex, oxidoreductase |
| Biological source | Rattus norvegicus (Norway rat) |
| Cellular location | Microsome: P06762 |
| Total number of polymer chains | 1 |
| Total formula weight | 31313.02 |
| Authors | Sugishima, M.,Sakamoto, H.,Omata, Y.,Hayashi, S.,Noguchi, M.,Fukuyama, K. (deposition date: 2002-03-18, release date: 2002-12-11, Last modification date: 2023-10-25) |
| Primary citation | Sugishima, M.,Sakamoto, H.,Omata, Y.,Hayashi, S.,Noguchi, M.,Fukuyama, K. 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 J.Biol.Chem., 277:45086-45090, 2002 Cited by PubMed Abstract: Heme oxygenase (HO) catalyzes physiological heme degradation consisting of three sequential oxidation steps that use dioxygen molecules and reducing equivalents. We determined the crystal structure of rat HO-1 in complex with heme and azide (HO-heme-N(3)(-)) at 1.9-A resolution. The azide, whose terminal nitrogen atom is coordinated to the ferric heme iron, is situated nearly parallel to the heme plane, and its other end is directed toward the alpha-meso position of the heme. Based on resonance Raman spectroscopic analysis of HO-heme bound to dioxygen, this parallel coordination mode suggests that the azide is an analog of dioxygen. The azide is surrounded by residues of the distal F-helix with only the direction to the alpha-meso carbon being open. This indicates that regiospecific oxygenation of the heme is primarily caused by the steric constraint between the dioxygen bound to heme and the F-helix. The azide interacts with Asp-140, Arg-136, and Thr-135 through a hydrogen bond network involving five water molecules on the distal side of the heme. This network, also present in HO-heme, may function in dioxygen activation in the first hydroxylation step. From the orientation of azide in HO-heme-N(3)(-), the dioxygen or hydroperoxide bound to HO-heme, the active oxygen species of the first reaction, is inferred to have a similar orientation suitable for a direct attack on the alpha-meso carbon. PubMed: 12235152DOI: 10.1074/jbc.M207267200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.9 Å) |
Structure validation
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