Crystal structure of human heme oxygenase-1.
Heme oxygenase catalyzes the first step in the oxidative degradation of heme. The crystal structure of heme oxygenase-1 (HO-1) reported here reveals a novel helical fold with the heme sandwiched between two helices. The proximal helix provides a heme iron ligand, His 25. Conserved glycines in the distal helix near the oxygen binding site allow close contact between the helix backbone and heme in addition to providing flexibility for substrate binding and product release. Regioselective oxygenation of the alpha-meso heme carbon is due primarily to steric influence of the distal helix.
Schuller
D J
DJ
Departments of Molecular Biology and Biochemistry, and Physiology and Biophysics, and Program in Macromolecular Structure, University of California, Irvine, California 92697-3900, USA.
Wilks
A
A
Ortiz de Montellano
P R
PR
Poulos
T L
TL
D001665:Binding Sites; D018360:Crystallography, X-Ray; D005998:Glycine / Q000737:chemistry / Q000378:metabolism; D006418:Heme / Q000737:chemistry / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000737:chemistry* / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006639:Histidine / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D008565:Membrane Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D018583:Pliability; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D012997:Solvents; D055672:Static Electricity; D013379:Substrate Specificity
D008024:Ligands; D008565:Membrane Proteins; D010446:Peptide Fragments; D012997:Solvents; D006418:Heme; D006639:Histidine; D007501:Iron; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D010100:Oxygen; D005998:Glycine