pUCS75, a stable high-copy-number Streptomyces--Escherichia coli shuttle vector which facilitates subcloning from pUC plasmid and M13 phage vectors.

A new Streptomyces-Escherichia coli shuttle vector, pUCS75, has been constructed to permit facile subcloning of DNA from the multiple cloning sites of the pUC plasmid and M13 phage vectors. In contrast to other commonly used shuttle vectors, pUCS75 retains the primary site for second-strand synthesis (ssi) of the parental streptomycete replicon, pIJ101. This sequence can not only enhance structural stability of the plasmid, but also confers on it an elevated copy number when replicated in Streptomyces. Consequently, the vector is useful for cloning sequences containing repeat structures and for allowing the high-level expression of cloned genes.