NUCLEOTIDE-SEQUENCE AND CHARACTERISTICS OF THE GENE, LPA-14, RESPONSIBLE FOR BIOSYNTHESIS OF THE LIPOPEPTIDE ANTIBIOTICS ITURIN-A AND SURFACTIN FROM BACILLUS-SUBTILIS RB14

Bacillus subtilis RB14 is a coproducer of the lipopeptide antibiotics iturin A and surfactin. Iturin A and surfactin have a similar structur e consisting of a seven-amino-acid cyclic peptide, linked by either hy droxy or ester peptide linkage, respectively, to the fatty acid part. A 10-kb fragment responsible for the production of the lipopeptide ant ibiotics iturin A and surfactin in B. subtilis RB14 was minimized and the nucleotide sequence of the region essential for the synthesis of t he lipopeptides was determined. A large open reading frame consisting of 224 amino acid residues was found. The gene, designated as lpa-14 ( lipopeptide antibiotic production of RB14), showed high homology with sfp and psf-1 (regulators for surfactin production in B. subtilis and Bacillus pumilus, respectively) and an unknown open reading frame, orf X, in the upstream region of the peptide antibiotic gramicidin S biosy nthesis operon of Bacillus brevis. The biosynthesis of surfactin and o f iturin A was shown to be coregulated by the same gene, lpa-14. It is suggested that a common regulation system might exist among these gen es for the production of peptide antibiotics in Bacillus species.