The peptide synthetase gene phsA from Streptomyces viridochromogenes is not juxtaposed with other genes involved in nonribosomal biosynthesis of peptides

The Streptomyces viridochromogenes peptide synthetase gene, phsA has no surrounding peptide antibiotic encoding genes. The gene encodes a protein with 622 amino acids. The carboxy terminal of the PhsA protein is essential for the peptide synthetase activity. The gene is involved in the production of phosphinothricin tripeptide. PhsA is necessary for the activation and condensation of one amino acid. Fragments of the phsA gene cloned into pGM vectors integrate into the phsA gene or outside the phsA locus in gene disrupted mutants.