1v8x
From Proteopedia
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|PDB= 1v8x |SIZE=350|CAPTION= <scene name='initialview01'>1v8x</scene>, resolution 1.85Å | |PDB= 1v8x |SIZE=350|CAPTION= <scene name='initialview01'>1v8x</scene>, resolution 1.85Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=OXY:OXYGEN+MOLECULE'>OXY</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=SUC:SUCROSE'>SUC</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] | + | |ACTIVITY= <span class='plainlinks'>[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] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1iw0|1IW0]], [[1iw1|1IW1]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1v8x FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1v8x OCA], [http://www.ebi.ac.uk/pdbsum/1v8x PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1v8x RCSB]</span> | ||
}} | }} | ||
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[[Category: Unno, M.]] | [[Category: Unno, M.]] | ||
[[Category: Yoshida, T.]] | [[Category: Yoshida, T.]] | ||
| - | [[Category: HEM]] | ||
| - | [[Category: OXY]] | ||
| - | [[Category: SO4]] | ||
| - | [[Category: SUC]] | ||
[[Category: helix]] | [[Category: helix]] | ||
[[Category: oxy]] | [[Category: oxy]] | ||
[[Category: protein-heme complex]] | [[Category: protein-heme complex]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:21:04 2008'' |
Revision as of 21:21, 30 March 2008
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| , resolution 1.85Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , | ||||||
| Activity: | Heme oxygenase, with EC number 1.14.99.3 | ||||||
| Related: | 1IW0, 1IW1
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of the Dioxygen-bound Heme Oxygenase from Corynebacterium diphtheriae
Overview
HmuO, a heme oxygenase of Corynebacterium diphtheriae, catalyzes degradation of heme using the same mechanism as the mammalian enzyme. The oxy form of HmuO, the precursor of the catalytically active ferric hydroperoxo species, has been characterized by ligand binding kinetics, resonance Raman spectroscopy, and x-ray crystallography. The oxygen association and dissociation rate constants are 5 microm(-1) s(-1) and 0.22 s(-1), respectively, yielding an O(2) affinity of 21 microm(-1), which is approximately 20 times greater than that of mammalian myoglobins. However, the affinity of HmuO for CO is only 3-4-fold greater than that for mammalian myoglobins, implying the presence of strong hydrogen bonding interactions in the distal pocket of HmuO that preferentially favor O(2) binding. Resonance Raman spectra show that the Fe-O(2) vibrations are tightly coupled to porphyrin vibrations, indicating the highly bent Fe-O-O geometry that is characteristic of the oxy forms of heme oxygenases. In the crystal structure of the oxy form the Fe-O-O angle is 110 degrees, the O-O bond is pointed toward the heme alpha-meso-carbon by direct steric interactions with Gly-135 and Gly-139, and hydrogen bonds occur between the bound O(2) and the amide nitrogen of Gly-139 and a distal pocket water molecule, which is a part of an extended hydrogen bonding network that provides the solvent protons required for oxygen activation. In addition, the O-O bond is orthogonal to the plane of the proximal imidazole side chain, which facilitates hydroxylation of the porphyrin alpha-meso-carbon by preventing premature O-O bond cleavage.
About this Structure
1V8X is a Single protein structure of sequence from Corynebacterium diphtheriae. Full crystallographic information is available from OCA.
Reference
Crystal structure of the dioxygen-bound heme oxygenase from Corynebacterium diphtheriae: implications for heme oxygenase function., Unno M, Matsui T, Chu GC, Couture M, Yoshida T, Rousseau DL, Olson JS, Ikeda-Saito M, J Biol Chem. 2004 May 14;279(20):21055-61. Epub 2004 Feb 13. PMID:14966119
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