To produce a new DNA comprising an isolated DNA coding for a PmeI restriction endonuclease and obtainable from Pseudomonas mendocina and used for the production, etc., of the restriction enzyme useful for a genetic engineering technique.

This new isolated DNA is an isolated DNA coding for a PMeI restriction endonuclease and obtainable from Pseudomonas mendocina. The PmeI restriction endonuclease is an enzyme naturally occurring in bacteria and used to cleave a DNA molecule into precise fragments for molecular cloning and gene characterization. The DNA is produced by amplifying a genomic Pseudomonas mendocina DNA according to a polymerase chain reaction(PCR) using a primer designed from an amino acid sequence thereof and cloning the amplified genomic DNA.