Crystallization and preliminary X-ray diffraction analysis of an oxidized state of Ohr from Xylella fastidiosa

• Author(s): Alves, Simone; Barbosa, G.; Cussiol, Jose; Guimar?es, B.; Medrano, F.; Netto, L.; Oliveira, M.; Ribeiro, Jadilson;
• Abstract: Xylella fastidiosa organic hydroperoxide-resistance protein (Ohr) is a dithiol-dependent peroxidase that is widely conserved in several pathogenic bacteria with high affinity for organic hydroperoxides. The protein was crystallized using the hanging-drop vapour-diffusion method in the presence of PEG 4000 as precipitant after treatment with organic peroxide (t-butyl hydroperoxide). X-ray diffraction data were collected to a maximum resolution of 1.8 Angstrom using a synchrotronradiation source. The crystal belongs to the hexagonal space group P6(5)22, with unit-cell parameters a = b = 87.66, c = 160.28 Angstrom. The crystal structure was solved by molecular-replacement methods. The enzyme has a homodimeric quaternary structure similar to that observed for its homologue from Pseudomonas aeruginosa, but differs from the previous structure as the active-site residue Cys61 is oxidized. Structure refinement is in progress.
• Publication Date: Feb 2004
• Journal: Acta Crystallographica Section D-Biological Crystallography