Restriction endonuclease sites and aromatic metabolic plasmid structure

Abstract

Plasmid DNA isolated from Pseudomonas putida strains which metabolize naphthalene (Nah +), salicylate (Sal +), or toluate (Tol +) contain multiple restriction endonuclease sites. Eco R1, Bam H1, and Hind III produce 10, 11 and 12 fragments respectively from plasmids NAH (∼48 Md) § and SAL (∼49 Md). The restriction fragments from NAH and SAL are identical in molecular weight for each enzyme except for 1 fragment which is ∼2 Md larger in SAL than its corresponding fragment in NAH. When the ∼80 Md TOL plasmid was treated with the same endonucleases, the yield was 17, 18 and 14 fragments, respectively; correspondence of the latter to the NAH-SAL fragments is suggested.