Cloning and secretive expression of the gene encoding the proteinaceous alpha-amylase inhibitor palm from Streptomyces corchorusii

A gene encoding the proteinaceous a-amylase inhibitor Palm was cloned and s equenced. Southern analysis and the amino acid sequence deduced from the cl oned gene indicated that Palm isoforms were encoded in the same gene. When the gene was expressed in Escherichia coli and Streptomyces lividans, recom binant Palm inhibitors were produced in the periplasmic space and in the cu lture supernatant, respectively. The purified inhibitors had different N-te rminal sequences from those of the authentic inhibitors.