Crystallization and preliminary crystallographic analysis of a D-aminoacylase from Alcaligenes faecalis DA1.

D-Aminoacylases catalyze the hydrolysis of N-acyl-D-amino acids into D-amino acids with the aid of zinc ions. The first D-aminoacylase crystal from Alcaligenes faecalis has been obtained in hanging drops at pH 5.6 by the vapour-diffusion method using 30% polyethylene glycol 4000 as precipitant. It belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 60.2, b = 76.6, c = 135.3 A. Reflections to 1.2 A resolution are observable. An initial atomic model with 472 residues has been built based on SeMet SAD data at 1.8 A resolution. Unexpectedly, the structure revealed a novel metal centre in the amidohydrolase superfamily.