De novo-engineered guide RNA-directed transposition with TnpB-family proteins.

De novo RNA-guided transposition systems using TnpB-family proteins achieve high-efficiency DNA insertion with orientation control in bacteria.

• Why it matters: Programmable DNA integration is crucial for precise genome engineering, but current systems may lack efficiency or specificity. Understanding how to improve these tools can expand their applications.
• What they did: The authors engineered bacteria-based transposition systems utilizing nuclease-dead TnpB-family proteins as guide RNA effectors, enabling high-efficiency, orientation-controlled DNA insertion, and combined them with exonuclease domains for cut-and-paste transposition; they also introduced mutations at the TniQ-TnsC interface to modulate off-site versus on-site activity.
• The result: These engineered systems demonstrate features not predicted from original enzymes, suggesting untapped potential for improvement, and show that specific mutations can enhance on-site activity while reducing off-site insertions, advancing the precision of guide-RNA-directed genome editing.