1n2f
CRYSTAL STRUCTURE OF P. AERUGINOSA OHR
OverviewOverview
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.
About this StructureAbout this Structure
1N2F is a Single protein structure of sequence from Pseudomonas aeruginosa pao1. Full crystallographic information is available from OCA.
ReferenceReference
Structural and functional characterization of the Pseudomonas hydroperoxide resistance protein Ohr., Lesniak J, Barton WA, Nikolov DB, EMBO J. 2002 Dec 16;21(24):6649-59. PMID:12485986 Page seeded by OCA on Sat May 3 02:00:18 2008