Cloning and characterization of the biosynthetic gene cluster of the bacterial RNA polymerase inhibitor tirandamycin from marine-derived Streptomyces sp. SCSIO1666

► We cloned, sequenced and analyzed the tirandamycin gene cluster. ► Seven genes were disrupted to support the tirandamycin biosynthetic pathway. ► TrdH as a positive regulator and TrdK as a negative regulator were identified. ► Inactivation of TrdI resulted in accumulation of two products. ► A model for tirandamycin biosynthesis is proposed.