ABSTRACT
This chapter reviews enzymes used for recombinant DNA technology that are produced by recombinant microbes. The type II restriction-modification system (R-M) consists of two genes, one coding for a restriction endonuclease and the other coding for a methyltransferase. Four methods are used to clone R-M genes: subcloning of a natural plasmid; cloning based on phage restriction; cloning based on vector modification, and two-step cloning. Many modifying enzymes have also been purified from recombinant microbes. Recent advances in recombinant DNA technology have made it possible to clone and overexpress many of the R-M enzymes and modifying enzymes useful for recombinant DNA technology. Another great advantage is the direct production of a modified version of some modifying enzymes in recombinant microbes. In short, production of these enzymes from recombinant microbes has made and will make many contributions to the advances in biological sciences.
