Fig. 5

CRISPR–dCas9 mediated transcription inhibition in the Pseudomonas putida KT2440. a Schematic representation of pCAS-ZE0 and its derivatives (pCAS-ZE1, pCAS-ZE2, pCAS-ZE3) used for transcription inhibition. Plasmid-borne enhanced green fluorescence protein (eGFP) was selected as target site. b Illustration of different dCas9 binding sites are indicated in the upstream sequence of plasmid pSEVA-eGFP. ZE1 and ZE2 were targeting the − 35 region of J5 promoter, and ZE3 was binding with Ribosome Binding Site (RBS). To examine the effect of selecting different DNA strand, ZE1 was designed to bind with template strand and ZE2 was located at the non-template strand. c KT2440 cells harboring dCas9 and eGFP plasmids were gathered with equal amount and exposed under UV light. Blank KT2440 cells were used as control. d Comparsion of the repression effectiveness of dCas9 binding with different target sites