Analysis of the leakage of gene repression by an artificial TetR-regulated promoter in cyanobacteria

摘要

BackgroundThere is a need for strong and tightly regulated promoters to construct more reliable and predictable genetic modules for synthetic biology and metabolic engineering. For this reason we have previously constructed a TetR regulated L promoter library for the cyanobacterium Synechocystis PCC 6803. In addition to the L03 promoter showing wide dynamic range of transcriptional regulation, we observed the L09 promoter as unique in high leaky gene expression under repressed conditions. In the present study, we attempted to identify the cause of L09 promoter leakage. TetR binding to the promoter was studied by theoretical simulations of DNA breathing dynamics and by surface plasmon resonance (SPR) biosensor technology to analyze the kinetics of the DNA–protein interactions.