TRANSPOSITION OF IS117 (THE STREPTOMYCES-COELICOLOR-A3(2) MINI-CIRCLE) TO AND FROM A CLONED TARGET SITE AND INTO SECONDARY CHROMOSOMAL SITES

IS 117, previously known as the 2.6 kb minicircle, is a transposable element found in Streptomyces coelicolor A3(2). It integrates predominantly into one preferred site when introduced into the closely related Streptomyces lividans 66, which lacks IS 117. This preferred integration site was deleted from the S. lividans chromosome by replacement with an erythromycin resistance gene delivered by a φ{symbol}C31 phage vector. When IS 117 was introduced into the resulting strain it integrated into many other sites, with some indication of site preference. By cloning a 200 by fragment centred on the preferred integration site onto a low copy number, self-transmissible Streptomyces plasmid derived from SCP2* it was shown that this sequence is sufficient to define the preferred site: IS 117 integrates efficiently into this sequence from its preferred site in the host chromosome and at a lower frequency from the plasmid into the preferred site on the S. lividans chromosome. © 1990 Springer-Verlag.