Restriction digests of the clone give the following sizes (kb): BamHI--9.2; BglII--9.2; SalI--9.2; NotI--9.2; PvuI--6.2, 1.8, 0.75, 0.45. Distributed in E. coli strain SP2 (ATCC 47089) which contains a pcnB mutation that limits pMB1-based plasmid copy number to approximately 10% of wild type. This is useful where high copy number may interfere with the fusion analysis. A high copy number, promoter-cloning plasmid that with very low levels of background lacZ expression. Permits detection of weak transcription signals. |