1N2F: Crystal Structure of P. Aeruginosa OHR

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.
PDB ID: 1N2FDownload
MMDB ID: 21509
PDB Deposition Date: 2002/10/22
Updated in MMDB: 2007/10 
Experimental Method:
x-ray diffraction
Resolution: 2.01  Å
Source Organism:
Similar Structures:
Biological Unit for 1N2F: dimeric; determined by author and by software (PISA)
Molecular Components in 1N2F
Label Count Molecule
Proteins (2 molecules)
Organic Hydroperoxide Resistance Protein
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB