We report the successful high-yield expression of Candida utilis uricase in Escherichia coli and the establishment of an efficient three-step protein purification protocol. The purity of the recombinant protein, which was confirmed to be C. utilis uricase by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometer analysis, was > 98% and the specific activity was 38.4 IU/mg. Crystals of C. utilis uricase were grown at 18A degrees C using 25% polyethylene glycol 3350 as precipitant. Diffraction by the crystals extends to 1.93 resolution, and the crystals belong to the space group P2(1)2(1)2(1) with unit cell parameters a = 69.16 , b = 139.31 , c = 256.33 , and alpha = beta = gamma = 90A degrees. The crystal structure of C. utilis uricase shares a high similarity with other reported structures of the homologous uricases from other species in protein database, demonstrating that the three-dimensional structure of the protein defines critically to the catalytic activities.