1t5p: Difference between revisions
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'''Human Heme Oxygenase Oxidation of alpha- and gamma-meso-phenylhemes''' | {{Structure | ||
|PDB= 1t5p |SIZE=350|CAPTION= <scene name='initialview01'>1t5p</scene>, resolution 2.11Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=1FH:12-PHENYLHEME'>1FH</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Heme_oxygenase Heme oxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.99.3 1.14.99.3] | |||
|GENE= HMOX1, HO1, HO ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]) | |||
}} | |||
'''Human Heme Oxygenase Oxidation of alpha- and gamma-meso-phenylhemes''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1T5P is a [ | 1T5P is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T5P OCA]. | ||
==Reference== | ==Reference== | ||
Human heme oxygenase oxidation of 5- and 15-phenylhemes., Wang J, Niemevz F, Lad L, Huang L, Alvarez DE, Buldain G, Poulos TL, de Montellano PR, J Biol Chem. 2004 Oct 8;279(41):42593-604. Epub 2004 Aug 5. PMID:[http:// | Human heme oxygenase oxidation of 5- and 15-phenylhemes., Wang J, Niemevz F, Lad L, Huang L, Alvarez DE, Buldain G, Poulos TL, de Montellano PR, J Biol Chem. 2004 Oct 8;279(41):42593-604. Epub 2004 Aug 5. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15297453 15297453] | ||
[[Category: Heme oxygenase]] | [[Category: Heme oxygenase]] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
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[[Category: heme oxygenase]] | [[Category: heme oxygenase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 14:14:07 2008'' | ||
Revision as of 15:14, 20 March 2008
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| , resolution 2.11Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | HMOX1, HO1, HO (Homo sapiens) | ||||||
| Activity: | Heme oxygenase, with EC number 1.14.99.3 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Human Heme Oxygenase Oxidation of alpha- and gamma-meso-phenylhemes
OverviewOverview
Human heme oxygenase-1 (hHO-1) catalyzes the O2-dependent oxidation of heme to biliverdin, CO, and free iron. Previous work indicated that electrophilic addition of the terminal oxygen of the ferric hydroperoxo complex to the alpha-meso-carbon gives 5-hydroxyheme. Earlier efforts to block this reaction with a 5-methyl substituent failed, as the reaction still gave biliverdin IXalpha. Surprisingly, a 15-methyl substituent caused exclusive cleavage at the gamma-meso-rather than at the normal, unsubstituted alpha-meso-carbon. No CO was formed in these reactions, but the fragment cleaved from the porphyrin eluded identification. We report here that hHO-1 cleaves 5-phenylheme to biliverdin IXalpha and oxidizes 15-phenylheme at the alpha-meso position to give 10-phenylbiliverdin IXalpha. The fragment extruded in the oxidation of 5-phenylheme is benzoic acid, one oxygen of which comes from O2 and the other from water. The 2.29- and 2.11-A crystal structures of the hHO-1 complexes with 1- and 15-phenylheme, respectively, show clear electron density for both the 5- and 15-phenyl rings in both molecules of the asymmetric unit. The overall structure of 15-phenylheme-hHO-1 is similar to that of heme-hHO-1 except for small changes in distal residues 141-150 and in the proximal Lys18 and Lys22. In the 5-phenylheme-hHO-1 structure, the phenyl-substituted heme occupies the same position as heme in the heme-HO-1 complex but the 5-phenyl substituent disrupts the rigid hydrophobic wall of residues Met34, Phe214, and residues 26-42 near the alpha-meso carbon. The results provide independent support for an electrophilic oxidation mechanism and support a role for stereochemical control of the reaction regiospecificity.
DiseaseDisease
Known diseases associated with this structure: Epiphyseal dysplasia, multiple, 5 OMIM:[602109], Heme oxygenase-1 deficiency OMIM:[141250], Osteoarthritis, hand, susceptibility to OMIM:[602109], Spondyloepimetaphyseal dysplasia OMIM:[602109]
About this StructureAbout this Structure
1T5P is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Human heme oxygenase oxidation of 5- and 15-phenylhemes., Wang J, Niemevz F, Lad L, Huang L, Alvarez DE, Buldain G, Poulos TL, de Montellano PR, J Biol Chem. 2004 Oct 8;279(41):42593-604. Epub 2004 Aug 5. PMID:15297453
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