A novel shuttle cosmid vector (pJAR4), based on pK505, was constructed for the cloning of Streptomyces DNA. It is a low-copy-number vector which determines hygromycin B-resistance as a selective marker and was used to clone the puromycin biosynthesis pathway from Streptomyces alboniger. Cosmids pJAR4 and pKC505 (which determines apramycin-resistance) stably co-transform both Streptomyces lividans and Streptomyces griseofuscus.