THERMOSTABLE RESTRICTION ENDONUCLEASES FROM THERMOPHILIC BACTERIA

Abstract

Restriction endonucleases are not only important for bacteria and archaea as their defense mechanism but they are considered as foundation of recombinant DNA technology. The whole empire of biotechnology depends upon type II restriction endonucleases isolated from the diversified array of bacteria. There are 4,096 known restriction enzymes, including 106 Type I, 3, 950 Type II, 21 Type III and 19 Type IV restriction enzymes. Among which 646 type II enzymes have been cloned and 611 have been sequenced. A number of restriction endonucleases have been isolated from thermophilic bacteria also, having higher thermal stability and tolerance to most of the chemical denaturants. In Restriction Enzyme Database, about 600 type II restriction enzymes have been listed showing growth temperature above 40C. Nowadays these enzymes have found their importance in isolating mutant strains and for production of antisense oligonucleotides. Thermostable restrictions enzymes are also applied as important tool for molecular biology, industrial works and in cellular processes.