Structural mechanism governing the directionality of bridge recombination

TL;DR - Cryo-EM structures reveal how IS621 bridge recombinase controls DNA excision and why it naturally favors insertion. The findings could guide the engineering of programmable bridge-editing tools.

• Resolves structural mechanisms governing bridge recombination directionality.
• Shows how IS621 bridge recombinase mediates DNA excision.
• Explains the system’s natural preference for DNA insertion.
• Provides a structural basis for designing programmable genome-editing technologies.