Cloning, purification, crystallization and X-ray crystallographic analysis of Ignicoccus hospitalis neelaredoxin

Abstract

Superoxide reductases (SORs) are metalloproteins which constitute the most recently identified oxygen-detoxification system in anaerobic and microaerobic bacteria and archaea. SORs are involved in scavenging superoxide radicals from the cell by catalyzing the reduction of superoxide (O2*-) to hydrogen peroxide and are characterized by a catalytic nonhaem iron centre coordinated by four histidine ligands and one cysteine ligand. Ignicoccus hospitalis, a hyperthermophilic crenarchaeon, is known to have a neelaredoxin-type SOR that keeps toxic oxygen species levels under control. Blue crystals of recombinant I. hospitalis oxidized neelaredoxin (14.1 kDa, 124 residues) were obtained. These crystals diffracted to 2.4 Å resolution in-house at room temperature and belonged to the hexagonal space group P6222 or P6422, with unit-cell parameters a = b = 108, c = 64 Å. Cell-content analysis indicated the presence of one monomer in the asymmetric unit. © 2010 International Union of Crystallography All rights reserved.