Crystallization and preliminary crystallographic analysis of the terminal oxygenase component of carbazole 1,9a-dioxygenase of Pseudomonas resinovorans strain CA10.

The terminal oxygenase component (CarAa) of carbazole 1,9a-dioxygenase from Pseudomonas resinovorans strain CA10 was crystallized at 293 K using the sitting-drop vapour-diffusion method under the following conditions: 0.1 M sodium citrate pH 5.6 in the presence of 0.5 M ammonium sulfate and 1.0 M lithium sulfate. By using additive reagents with the crystallizing condition, improved diffraction was obtained from the crystals. Preliminary X-ray diffraction analysis indicated that CarAa crystals are hexagonal and belong to space group P6(2) or P6(4), with unit-cell parameters a = b = 244.5, c = 65.7 A, alpha = beta = 90.0, gamma = 120.0 degrees. Diffraction data were collected to 3.0 A resolution. The V(M) value is 2.16 A(3) Da(-1), which indicates a solvent content of 43.0%. This is the first report of crystallization of the terminal oxygenase component of an angular-type dioxygenase.