Streptomyces griseoviridis 2464-S5 produces prodigiosin R1, a tripyrrole antibiotic, and roseophilin, a structurally related compound containing two pyrrole and one furan rings. A gene cluster for the biosynthesis of a prodigiosin was identified in S. griseoviridis. The cluster consisted of 24 open reading frames, including 21 genes (rphD-rphZ) homologous to prodigiosin biosynthesis genes in the red cluster in Streptomyces coelicolor A3(2). The expression of rphN in S. coelicolor lacking redN restored the production of prodigiosin.