We previously identified a polyketide synthase gene cluster, aur1, responsible for the production of the angucycline antibiotic auricin in Streptomyces aureofaciens CCM 3239. A sequence analysis of the aur1 flanking regions revealed the presence of several genes encoding proteins homologous to those for Streptomyces linear plasmid replication, partitioning and telomere-binding. Pulse-field gel electrophoresis detected the single, 240-kb linear plasmid, pSA3239, in S. aureofaciens CCM3239. The presence of the auricin cluster in pSA3239 was confirmed by several approaches. In addition to aur1, pSA3239 also carries a large number of regulatory genes, and two gene clusters involved in the production of secondary metabolites: the aur2 cluster for an unknown secondary metabolite and the bpsA cluster for the blue pigment indigoidine.