Targeted DNA modification triggers precise repair in bacteria and causes mutations in complex cells

This approach enables the targeted addition of ADP-ribosyl moieties to DNA, leading to distinct editing outcomes in different organisms.

• Base editors create precise genomic edits without causing DNA breaks but only explore a limited range of modifications.
• The bacterial antiphage toxin DarT2 is used to append chemical groups to DNA, expanding the potential for genome editing.
• In tested bacteria, the targeted addition of ADP-ribosyl moieties facilitates homologous recombination, allowing for flexible genome editing.
• In yeast, plant, and human cells, the modifications result in the conversion of thymine to adenine or a mix of adenine and cytosine, with minimal insertions or deletions.
• The method, termed append editing, provides new editing possibilities that current base editors cannot achieve.

Simplified