Mok et al. describe the discovery of a bacterial toxin (DddA) that acts as a cytidine deaminase. Subsequent adaptation of the enzyme included adding a mitochondrial targeting signal and fusion to TALE proteins to facilitate binding to DNA at a specific location. The mitochondrial base editor can make C–>G and T–>A changes. Although some limitations are described, DddA-derived cytosine base editor (DdCBE) is another powerful tool that originated from the David Liu Lab.

Reference: Mok et al. A bacterial cytidine deaminase toxin enables CRISPR-free mitochondrial base editing. Nature (2020). doi.org/10.1038/s41586-020-2477-4
See also: Aushev & Herbert. Mitochondrial genome editing gets precise. Nature 583, 521-522 (2020). doi:10.1038/d41586-020-01974-6

Keywords: mitochondria, base editor, cytidine deaminase

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