ISOLATION AND CHARACTERIZATION OF SFP - A GENE THAT FUNCTIONS IN THE PRODUCTION OF THE LIPOPEPTIDE BIOSURFACTANT, SURFACTIN, IN BACILLUS-SUBTILIS

The sfp gene is required for cells of Bacillus subtilis to become prod ucers of the lipopeptide antibiotic surfactin. sfp was isolated and it s nucleotide sequence was determined. sfp was expressed in Escherichia coli and its putative product was purified for use in antibody produc tion and in amino acid sequence analysis. The gene was plasmid-amplifi ed in B. subtilis, where it conferred a Srf+ phenotype on sfp0 (surfac tin non-producing) cells. Overproduction of Sfp in B. subtilis did not cause production of an increased amount of surfactin and resulted in the repression of a lacZ transcriptional fusion of the srfA operon, wh ich encodes enzymes that catalyze surfactin synthesis. We propose that sfp represents an essential component of peptide synthesis systems an d also plays a role, either directly or indirectly, in the regulation of surfactin biosynthesis gene expression.