Esterase from the oil-degrading Acinetobacter lwoffii RAG-1: Sequence analysis and over-expression in Escherichia coli

The est gene encoding an esterase from Acinetobacter lwoffii RAG-1 was cloned into E. coli under the control of the P_L promoter of the phage λ. 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. lwoffiiRAG-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.