A simple and general approach to control the activity of DNA processing enzymes

DNA processing enzymes, such as DNA polymerases and endonucleases, have found many applications in biotechnology, molecular diagnostics, and synthetic biology, among others. The development of enzymes with controllable activity, such as hot-start or light-activatable versions, has boosted their applications and improved the sensitivity and specificity of the existing ones. However, current approaches to produce controllable enzymes are experimentally demanding to develop and case specific. Here, we introduce a simple and general method to design light-start DNA processing enzymes. In order to prove its versatility, we applied our method to three DNA polymerases commonly used in biotechnology, including the Phi29 (mesophilic), Taq and Pfu polymerases, and one restriction enzyme. Light-start enzymes showed suppressed polymerase, exonuclease and endonuclease activity until they were re-activated by an UV pulse. Finally, we applied our enzymes to common molecular biology assays, and showed comparable performance to commercial hot-start enzymes. ### Competing Interest Statement P.T and A.M.V are co-inventors of an European patent application (EP21194389.9) covering the results contained in this article.