Escherichia coli is widely used in synthetic biology. It offers the advantage of being a comparatively simple and well-understood model organism while being easy to handle in the laboratory environment. Also, an expansion of the genetic code has already been successfully implemented in E. coli multiple times [1]–[4] by introducing an orthogonal tRNA/aminoacyl-synthetase pair.
Therefore, working in E. coli is an obvious choice.
Due to a limited range of tRNA/aminoacyl-synthetase pairs for non-canonical amino acids in general and especially for those that act orthogonally in E. coli, photocaging serine in the active site of subtilisin E with DMNB-serine is currently not possible. Hence, another strategy is needed to produce temporarily inactive proteases. This part of the project focuses on utilizing the maturation process of subtilisin E.