Institute of Biochemistry, Biological Research Center P.O.B. 521, H-6701, Szeged, Hungary Tel. (62J-23-022
Abstract:
A stable copy-number mutant of a pBR322-derived plasmid was isolated. The mutation was found to be a single G → T transversion located near the 3' end of a DNA segment coding for the regulatory RNA I. The resulting copy number for this plasmid is approx. 1000 per cell or 65 % of total cellular DNA. Several cloning vectors have been constructed from this copy-number mutant and their practical application is discussed.