Precise, minimally evolved adenine base editors generated through mutation reversion analysis

The initial development of adenine base editors (ABEs), which facilitate A•T to G•C base pair changes in the genome, used directed evolution to install 14 mutations into the wild-type deaminase TadA, producing the first-of-its-kind editor ABE7.10. Here we study the installed mutations' impacts on TadA fitness using comprehensive reversion analysis and apply our results to engineer more efficient, precise editors. By measuring activity in both human and Escherichia coli host systems, we categoriz