Expanding the base editor toolkit; plus new antibody discovery platforms and more

A pair of Nature Communications studies from Tian-Lin Cheng’s lab at Fudan University describe a set of base editors engineered to have both A- and C-editing activity, and another set that was miniaturized and optimized for precision and potency. Both approaches involved engineering tRNA-specific adenosine deaminase (TadA), a bacterial-derived enzyme that forms the basis for adenine base editors.

The first study described 25 TadA orthologs engineered to generate functional Cas9-based adenine base editors (ABEs), cytosine base editors (CBEs) and fusion adenine–cytosine base editors (ACBEs); the latter offer greater flexibility than previously available A- or C-restricted deaminases. Five of the orthologs with improved editing efficiency and lowered DNA- and RNA-off-target effects and genotoxicity were selected for further development. ...