Abstract:
Saccharopolyspora erythraea chromosomal DNA digested extensively with PstI has been cloned in shuttle vector pUWL201, which is transformed into protoplast of Streptomyces lividans TK23. Nine transformants are obtained by double antibiotic resistant screening. The nine plasmids are extracted and re transformed, then about 200 transformants are screened on plate containing erythromycin, respectively. It is found that three transformants grow well on resistant plate, designated pLP42, pLP1b and pLP44, respectively. With the electrophresis analysis of restriction fragments of pLP42, our experiment shows that pLP42 contains about 3.0kb foreign fragment from S.erythraea chromosomal DNA, and a section of vector pUWL201 has been deleted. A 1.7kb KpnI fragment from pLP42 has been cloned and sequenced. Compared with the ermE sequence in genebank, the cloned S.erythraea chromosome fragment firmly contains the antibiotic resistance gene.