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Cited by 83

The DOI matches its Crossref record; 58 of the 58 references it cites were found in a registry or an index.

Crystal Structure of the Dioxygen-bound Heme Oxygenase from Corynebacterium diphtheriae

Unno, Masaki, Matsui, Toshitaka, Chu, Grace C., Couture, Manon, Yoshida, Tadashi, Rousseau, Denis L., Olson, John.S., Ikeda-Saito, Masao·2004·Journal of Biological Chemistry
DOI 10.1074/jbc.m400491200
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Abstract

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.

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Crossref · 10.1074/jbc.m400491200

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Figures

FIG. 1 Schematics of heme oxygenase catalytic intermediates.
FIG. 1 Schematics of heme oxygenase catalytic intermediates.CC-BY · From the PDF
FIG. 2 Resonance Raman spectra of the oxygen-bound form of the heme complex of HmuO. A , the 16 O2-bound HmuO complex. B , 18 O2-bound HmuO complex. C , difference spectrum between A and B. D , 16 O2- 18 O2 difference spectrum of the oxy form of the heme complex of rat HO-1 (20).
FIG. 2 Resonance Raman spectra of the oxygen-bound form of the heme complex of HmuO. A , the 16 O2-bound HmuO complex. B , 18 O2-bound HmuO complex. C , difference spectrum between A and B. D , 16 O2- 18 O2 difference spectrum of the oxy form of the heme complex of rat HO-1 (20).CC-BY · From the PDF
Image 3
CC-BY · From the PDF
FIG. 4 Structure of the immediate vicinity of the bound dioxygen. The distal pocket Gly residues and the bound dioxygen are shown in a CPK model, and the heme is illustrated in a ball-and-stick diagram. Carbon, nitrogen, and oxygen atoms of the heme and Gly residues are shown in gray , blue , and red , respectively. The bound dioxygen molecule is shown in magenta . Top , view from the pyrrole A; bottom , view from the distal side of the heme.
FIG. 4 Structure of the immediate vicinity of the bound dioxygen. The distal pocket Gly residues and the bound dioxygen are shown in a CPK model, and the heme is illustrated in a ball-and-stick diagram. Carbon, nitrogen, and oxygen atoms of the heme and Gly residues are shown in gray , blue , and red , respectively. The bound dioxygen molecule is shown in magenta . Top , view from the pyrrole A; bottom , view from the distal side of the heme.CC-BY · From the PDF

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Citations

Cites

Research works printed but not linked: 2

  1. Ikeda-Saito, 2003, 858, 97
  2. Jones, 1991, Acta Crystallogr. Sect. A, 47, 100

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Metadata

Authors
Unno, M., Matsui, T., Chu, G. C., Couture, M., Yoshida, T., Rousseau, D. L., Olson, J. S., & Ikeda-Saito, M.
Venue
Journal of Biological Chemistry
Publisher
Elsevier BV
Published
2004-05
Volume
279
Issue
20
Pages
21055-21061
ISSN
0021-9258
DOI
10.1074/jbc.m400491200
Cited by
83
References
58
Language
en
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