Structural and functional characterization of the Pseudomonas hydroperoxide resistance protein Ohr Journal Article
| Authors: | Lesniak, J.; Barton, W. A.; Nikolov, D. B. |
| Article Title: | Structural and functional characterization of the Pseudomonas hydroperoxide resistance protein Ohr |
| Abstract: | Bacteria have developed complex strategies to detoxify and repair damage caused by reactive oxygen species. These compounds, produced during bacterial aerobic respiration as well as by the host immune system cells as a defense mechanism against the pathogenic microorganisms, have the ability to damage nucleic acids, proteins and phospholipid membranes. Here we describe the crystal structure of Pseudomonas aeruginosa Ohr, a member of a recently discovered family of organic hydroperoxide resistance proteins. Ohr is a tightly folded homodimer, with a novel α/β fold, and contains two active sites located at the monomer interface on opposite sides of the molecule. Using in vitro assays, we demonstrate that Ohr functions directly as a hydroperoxide reductase, converting both inorganic and organic hydroperoxides to less toxic metabolites. Site-directed mutagenesis confirms that the two conserved cysteines in each active site are essential for catalytic activity. We propose that the Ohr catalytic mechanism is similar to that of the structurally unrelated peroxiredoxins, directly utilizing highly reactive cysteine thiol groups to elicit hydroperoxide reduction. |
| Keywords: | protein expression; unclassified drug; nonhuman; protein conformation; peroxidase; protein analysis; in vitro study; drug resistance; dose-response relationship, drug; enzyme activity; bacteria (microorganisms); time factors; bacterial protein; bacterial proteins; amino acid sequence; molecular sequence data; sequence homology, amino acid; protein purification; escherichia coli; crystal structure; models, molecular; dimerization; crystallography, x-ray; mutagenesis, site-directed; binding sites; hydrogen peroxide; oxidative stress; high performance liquid chromatography; protein folding; protein structure; peroxiredoxin; enzyme specificity; site directed mutagenesis; catalytic domain; protein structure, secondary; enzyme mechanism; enzyme active site; pseudomonas aeruginosa; pseudomonas; negibacteria; peroxidases; priority journal; article; organic hydroperoxides; protein ohr; bacterial resistance; bacterial survival |
| Journal Title: | EMBO Journal |
| Volume: | 21 |
| Issue: | 24 |
| ISSN: | 0261-4189 |
| Publisher: | Wiley Blackwell |
| Date Published: | 2002-12-16 |
| Start Page: | 6649 |
| End Page: | 6659 |
| Language: | English |
| DOI: | 10.1093/emboj/cdf670 |
| PUBMED: | 12485986 |
| PROVIDER: | scopus |
| PMCID: | PMC139091 |
| DOI/URL: | |
| Notes: | Export Date: 14 November 2014 -- Source: Scopus |
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