A general approach for identifying and cloning peptide synthetase genes.

A wide variety of bioactive peptides are synthesized nonribosomally by large multienzyme complexes employing the thiotemplate mechanism. Based on the known and highly conserved structures of several genes encoding multifunctional peptide synthetases, we developed a universal polymerase chain reaction (PCR) approach for amplifying, cloning and identifying parts of putative peptide synthetase genes. We showed, by cloning fragments of peptide synthetase genes from the phaseolotoxin-producing strain Pseudomonas syringe pv. phaseolica and from Bacillus licheniformis, which produces the branched peptide antibiotic bacitracin, that this approach is applicable. It gives a new and potentially general access to the biosynthetic genes of many nonribosomally synthesized peptides.