Crystallization and preliminary X‐ray analysis of a bacterial l ‐amino‐acid oxidase from Rhodococcus opacus

l ‐Amino‐acid oxidases (EC 1.4.3.2) catalyse the stereospecific oxidative deamination of an l ‐amino‐acid substrate to an α‐keto acid with the production of ammonia and hydrogen peroxide. In this study, the crystallization and preliminary X‐ray analysis of a bacterial l ‐amino‐acid oxidase from Rhodococcus opacus (RoLAAO) is described. RoLAAO is a dimeric protein consisting of two identical subunits of 489 amino acids with a calculated molecular weight of 54.2 kDa and a non‐covalently bound FAD molecule. RoLAAO was crystallized by the vapour‐diffusion method in two different space groups: P 2 1 2 1 2 1 (unit‐cell parameters a = 65.7, b = 109.7, c = 134.4 Å) and C 222 1 (unit‐cell parameters a = 68.3, b = 88.4, c = 186.6 Å). Both crystal forms diffracted X‐rays to a resolution of at least 1.6 Å.