Crystallization of catechol-1,2 dioxygenase from Pseudomonas arvilla C-1

The metalloenzyme catechol 1,2-dioxygenase from Pseudomonas arvilla C-1 consists of three isozymes formed by combinations of two non-identical subunits; αα, αβ and ββ; with molecular masses of 59,000, 63,000 and 67,000 Da, respectively. The αα isozyme crystallizes in the orthorhombic space group C222₁ with unit cell dimensions a = 62.7 Å, b = 71.5 Å, c = 187.1 Å. The rectangular plates diffract to 2.6 Å resolution. This is the first dioxygenase to be crystallized that uses catechol as a substrate. Comparison of the structure of this enzyme with protocatechuate 3,4-dioxygenase will provide basic information about the mechanisms of subunit association, substrate selectivity, and the origins of metabolic diversity in enzymes.