New Gene-Editing Enzyme Converts A-T to G-C

A new enzyme, called an adenine base editor (ABE), can convert selected A-T base pairs to G-C base pairs, and do so without cleaving DNA. ABE’s capabilities may be attributed to its main components: an “evolved” transfer RNA adenosine deamininase (TadA), a Cas9 nickase, and a guide RNA.ABE can directly repair the type of single-letter changes in the human genome that account for approximately half of human disease-associated point mutations. These mutations are associated with