Expression, crystallization and preliminary X-ray crystallographic study of ethanolamine ammonia-lyase from Escherichia coli.

Ethanolamine ammonia-lyase (EAL) catalyzes the adenosylcobalamin-dependent conversion of ethanolamine to acetaldehyde and ammonia. The wild-type enzyme shows a very low solubility. N-terminal truncation of the Escherichia coli EAL beta-subunit dramatically increases the solubility of the enzyme without altering its catalytic properties. Two deletion mutants of the enzyme [EAL(betaDelta4-30) and EAL(betaDelta4-43)] have been overexpressed, purified and crystallized using the sitting-drop vapour-diffusion method. Crystals of EAL(betaDelta4-30) and EAL(betaDelta4-43) diffracted to approximately 8.0 and 2.1 A resolution, respectively.