Engineering T7 RNA polymerase-cascaded systems controlled by nisin and theophylline for protein overexpression and targeted gene mutagenesis in <i>Lactococcus lactis</i>.

ABSTRACT: Lactococcus lactis serves as an important platform for heterologous protein production, with the nisin-controlled gene expression (NICE) system being widely employed for regulated protein overexpression. However, the NICE system relies on the native RNA polymerase, which limits transcriptional efficiency, and there remains a lack of tools enabling continuous target gene mutagenesis in L. lactis. In this study, we enhanced the NICE system by integrating the highly processive T7 RNA polymerase (T7RNAP) to boost protein expression. A theophylline-dependent riboswitch, RbxE, was incorporated into the nisin-induced promoter to mitigate the toxicity caused by basal T7RNAP expression in Escherichia coli. Directed mutagenesis of the riboswitch region between the stem-loop and

SUBMITTER: Huang Y 

PROVIDER: S-EPMC12269272 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature