Esterase from the oil-degradingAcinetobacter lwoffiiRAG-1: Sequence analysis and over-expression inEscherichia coli

The est gene encoding an esterase from Acinetobacter lwoffii RAG-1 was cloned into E. coli under the control of the PL promoter of the phage lambda. The N-terminal sequence of the first 20 amino acids of the heterologous expressed esterase corresponded to that obtained from the nucleotide sequence. Antibodies prepared against the over-expressed recombinant esterase in E. coli were used to locate the enzyme primarily in the membrane fractions of A. lwoffii RAG-1. Comparison with homologous proteins from both eukaryotic and prokaryotic organisms suggest that the RAG-1 esterase exhibits sequence motifs characteristic of both serine proteases and of lipases.