Preliminary crystallographic study of protocatechuate 3,4-dioxygenase from Pseudomonas aeruginosa

The enzyme protocatechuate 3,4-dioxygenase (EC 1.13.11.3) from Pseudomonas aeruginosa consisting of eight identical subunits (total Mr = 783,100) crystallizes in the monoclinic space group 12 with unit cell dimensions a = 204, b = 129, c = 137 A, and beta = 97.5 degrees. The measured density is 1.26 g ml-1. The Matthews coefficient is 2.27 A3/dalton. The large rod-like crystals diffract to about 2.5 A resolution. The asymmetric unit contains one-half of the enzyme and the enzyme contains an exact 2-fold axis of symmetry.