endonuclease restriction enzymes

endonuclease restriction enzymes

bacterial ENZYMES capable of cleaving DNA at or near points where specific NUCLEOTIDE sequences occur, a function thought to be important in defending an organism against invasion by foreign DNA (see MODIFICATION AND RESTRICTION). Such enzymes have been used extensively to map the base sequences of DNA controlling, for example, the structure of HAEMOGLOBIN molecules, and to construct recombinant vectors in GENETIC ENGINEERING.