Abstract
In this study, three kinds of promoter-RBS libraries, i.e., constitutive promoter-RBS library, repressor-regulated promoter-RBS library and activator-regulated promoter-RBS library, are constructed for the systematic genetic circuit design by identifying the kinetic strengths of promoter-RBS components. Based on the input/output (I/O) characteristics and concentrations of external inducers, the genetic transistor can be designed for genetic amplification or genetic switching. By the different selections of promoter-RBS components and regulations of inducer concentrations, the different design specifications of genetic transistor can be obtained. According to the dynamic model of genetic transistor, a design methodology of genetic transistor via GA-based searching algorithm is developed to search for a set of promoter-RBS components and concentrations of inducers from the corresponding promoter-RBS libraries to achieve a prescribed I/O characteristic of genetic transistor. Furthermore, according to design specifications of different kind of genetic transistors, a look-up table is built for genetic transistor design, from which we could easily select an adequate set of promoter-RBS components and concentrations of inducer. This will save much time on trial-and-error in experimental procedure for a genetic transistor with a desired I/O characteristic. Finally, we demonstrate the applicability of our methodology by designing genetic transistors respectively for a desired linear amplifier and a desired switching I/O response via in silico simulation based on promoter-RBS libraries.