1N2F

CRYSTAL STRUCTURE OF P. AERUGINOSA OHR

Summary for 1N2F

• Entry DOI: 10.2210/pdb1n2f/pdb
• Descriptor: Organic Hydroperoxide Resistance Protein, 2,3-DIHYDROXY-1,4-DITHIOBUTANE (3 entities in total)
• Functional Keywords: peroxide reductase, oxidoreductase
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 2
• Total formula weight: 29489.53

Authors

Lesniak, J.,Barton, W.A.,Nikolov, D.B. (deposition date: 2002-10-22, release date: 2002-12-25, Last modification date: 2024-02-14)

Primary citation

Lesniak, J.,Barton, W.A.,Nikolov, D.B.
Structural and functional characterization of the Pseudomonas hydroperoxide resistance protein Ohr
Embo J., 21:6649-6659, 2002

PubMed 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 alpha/beta 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.

PubMed: 12485986
DOI: 10.1093/emboj/cdf670

Experimental method

X-RAY DIFFRACTION (2.01 Å)