Figure 6.

Summary of T3SS-mediated genome editing. ExoS54-TALEN fusion proteins are produced inside bacterial cells and directly injected into the host cytosol through the bacterial T3SS needle. The injected ExoS54-TALEN proteins target to nucleus, find their target sequences on the chromosome, and introduce DSBs. In the presence of the ssDNA template (delivered by transfection), the DSB triggers homologous recombination, resulting in the desired base changes on the chromosomally encoded gfp or hprt1 gene. Abbreviations: DSB, double-strand break; ExoS54, exotoxin S N-terminal 54 amino acids fused with Cre recombinase; GFP, green fluorescent protein; HR, homologous recombination; ssDNA, single-strand DNA; T3SS, type III secretion system; TALEN, transcription activator-like effector nuclease.