Evolutionary analysis of the 7.1-kb beta-lactamase-specifying R-plasmid of Neisseria gonorrhoeae by restriction endonucleases.

A physical map of restriction enzyme sites was made for the large beta-lactamase-specifying gonococcal R-plasmid (pMR0360) isolated in 1976. Single sites in the plasmid were mapped for 11 endonucleases, and multiple sites of cleavage were mapped for 17 other enzymes. Conclusions about the structure and origin of this plasmid are discussed.