CRYSTALLIZATION AND PRELIMINARY-X-RAY STUDIES OF HORF6, A NOVEL HUMANANTIOXIDANT ENZYME

HORF6 is a member of the novel antioxidant enzyme family found in huma ns. A recombinant form of hORF6 expressed and purified from E. coli ha s been crystallized by the hanging-drop method using various PEG's as precipitating agents. HORF6 crystallizes in two different monoclinic s pace groups, P2(1) and C2. The P2(1) crystals have unit-cell dimension s of a = 47.85, b = 75.17, c = 63.30 Angstrom and beta = 110.21 degree s and contain two monomers per asymmetric unit, while the C2 crystals have unit-cell dimensions of a = 165.27, b = 95.44, c = 166.44 Angstro m and beta = 128.97 degrees and contain more than six monomers per asy mmetric unit. The P2(1) crystals with the smaller unit cell diffract X -rays better and behave well for the X-ray analysis. A native data set from a single crystal of the P2(1) space group has been collected to 2.0 Angstrom resolution.