CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION STUDIES OF EXPRESSED PSEUDOMONAS-PUTIDA CATECHOL 2,3-DIOXYGENASE

Crystals of recombinant Pseudomonas putida catechol 2,3-dioxygenase, m etapyrocatechase, composed of four identical subunits, each with a mol ecular mass of 35 kDa and one nonheme ferrous iron, have been grown by the vapor diffusion method using sodium citrate as the precipitant. R epeated macroseeding and the addition of ethanol to protein solutions were together effective for obtaining crystals suitable for further cr ystallographic characterization, The crystals belong to the tetragonal space group P4(2)2(1)2 with unit-cell dimensions of a = b = 266 Angst rom, c = 60 Angstrom, They diffracted beyond 2.5 Angstrom resolution w ith synchrotron radiation, Assuming that one tetramer (alpha-Fe2+), is contained in an asymmetric unit, the crystal volume per unit molecula r mass, V-m, is calculated to be 3.8 Angstrom(3)/Da, which corresponds to the solvent content of 67.6%.