FIG. 2.

Effects of deletions, insertions, and substitutions in CIS of the RepA-producing plasmid on the copy number of ori^B and ori^L plasmids. Copy number was determined by assaying the CAT activity of E. coli strain JP3438 carrying the ori plasmids, in the absence of IPTG. The values shown are the average of at least six independent determinations. trpA^ter, 28-bp trpA transcription terminator; Km⁵⁵ and Km⁶³, 55- and 63-bp DNA fragments amplified from the coding sequence of aminoglycoside 3′-phosphotransferase; NC, no transformants detected, regardless of whether the pAM34 replicon was induced or not; ND, not done; H, copy number too high for accurate determination; →, RNA transcript.