Transduction of plasmid DNA containing the ermE gene and expression of erythromycin-resistance in streptomycetes.

Plasmid pIJ7021) is a useful vector for the cloning and expression of streptomycete and mammalian genes in Streptomyces lividans.2~4) pIJ702 or its derivatives have broad host range, replicating in many Streptomyces species and in other actinomycetes (see ref 2~6 and refs therein). We have been interested in expanding the utility of pIJ702 by making it transducible. We cloned a segment of bacteriophage FP43 DNA(hft) into the Sph I site ofpIJ702, and the resulting plasmid (pRHBlOl) was transducible by FP43 from Streptomyces griseofuscus ATCC23916 into many streptomycetes.6~ 8) The hft region mediating transduction contains an origin for headful packaging, or pac site.9) To use this transducible plasmid to genetically manipulate streptomycetes, we needed to know if DNA could be inserted into pRHBlOl without disrupting transduction or plasmid stability. To test this, we inserted the ermE gene from Saccharopolyspora erythraea10'1^ into the Kpn I site of pRHBlOl (Fig. 1) and introduced the resulting