The enzymes of thermophilic organisms, because of their high thermostability, have been used widely not only for the study of the molecular mechanism of thermostability but also for the elucidation of structure and function relationship of the enzymes. In our laboratory we have purified and studied several enzymes from an extreme thermophile, Thermus thermophiles HB8, which was isolated from Japanese hot spring 1 . This organism is a gram-negative, nonsporulating rod shaped bacterium with its maximum growing temperature at 85°C and the minimum at 47°C. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.