Molecular cloning of enantioselective ester hydrolase fromBacillus pumilusDBRL-191

A gene from Bacillus pumilus expressed under its native promoter was cloned in Escherichia coli. Recombinant B. pumilus esterase(BPE) affects the kinetic resolution of racemic mixtures such as unsubstituted and substituted 1-(phenyl)ethanols (E � 33–103), ethyl 3-hydroxy-3-phenylpropanoate (E � 45–71), trans-4-fluorophenyl-3-hydroxymethyl-N-methylpiperidine (E � 10–13) and ethyl 2- hydroxy-4-phenylbutyrate (E � 7). The enzyme is composed of a 34-amino acid signal peptide and a 181-amino acid mature protein corresponding to a molecular weight of �19.2 kD and pI � 9.4. 3-D the structural model of the enzyme built by homology modelling using the atomic coordinates from the crystal structure of B. subtilis lipase (LipA) showed a compact minimal a/b hydrolase fold