Restriction endonuclease mapping and cloning of Mycobacterium intracellulare plasmid pLR7.

A restriction map of Mycobacterium intracellulare plasmid pLR7 was developed. This 15.3-kb plasmid had unique sites for BamHI, HindIII, and XbaI. Various large fragments of pLR7 were cloned into pBR322 or pHP34 and propagated in Escherichia coli. A hybrid pLR7 ::pBR322 plasmid carrying the complete pLR7 sequence was constructed by joining the plasmids at their HindIII sites. The construction of these hybrids will facilitate the analysis and manipulation of pLR7 and may allow the development of this plasmid as a model system for genetic analysis in mycobacteria.