A novel TALE nuclease scaffold enables high genome editing activity in combination with low toxicity

Sequence-specific nucleases represent valuable tools for precision genome engineering. Traditionally, zinc-finger nucleases (ZFNs) and meganucleases have been used to specifically edit complex genomes. Recently, the DNA binding domains of transcription activator-like effectors (TALEs) from the bacterial pathogen Xanthomonas have been harnessed to direct nuclease domains to desired genomic loci. In this study, we tested a panel of truncation variants based on the TALE protein AvrBs4 to identify TALE nucleases (TALENs) with high DNA cleavage activity. The most favorable parameters for efficient DNA cleavage were determined in vitro and in cellular reporter assays. TALENs were designed to disrupt an EGFP marker…