{"id":"doi:10.1038/s41587-022-01533-6","kind":"article","title":"Evolution of an adenine base editor into a small, efficient cytosine base editor with low off-target activity","authors":["Neugebauer ME","Hsu A","Arbab M","Krasnow NA","McElroy AN","Pandey S","Doman JL","Huang TP","Raguram A","Banskota S","Newby GA","Tolar J","Osborn MJ","Liu DR"],"author_count":14,"year":2023,"published":"2022-11-10","venue":"Nature biotechnology","cited_by":238,"doi":"10.1038/s41587-022-01533-6","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1038/s41587-022-01533-6","archive_url":"https://space-kitty.com/papers/doi:10.1038/s41587-022-01533-6","updated":null,"pmid":"36357719","pmcid":"PMC10188366","openalex_id":null,"pdf_url":"https://europepmc.org/articles/PMC10188366/pdf","abstract":"Cytosine base editors (CBEs) are larger and can suffer from higher off-target activity or lower on-target editing efficiency than current adenine base editors (ABEs). To develop a CBE that retains the small size, low off-target activity and high on-target activity of current ABEs, we evolved the highly active deoxyadenosine deaminase TadA-8e to perform cytidine deamination using phage-assisted continuous evolution. Evolved TadA cytidine deaminases contain mutations at DNA-binding residues that alter enzyme selectivity to strongly favor deoxycytidine over deoxyadenosine deamination. Compared to commonly used CBEs, TadA-derived cytosine base editors (TadCBEs) offer similar or higher on-target activity, smaller size and substantially lower Cas-independent DNA and RNA off-target editing activity. We also identified a TadA dual base editor (TadDE) that performs equally efficient cytosine and adenine base editing. TadCBEs support single or multiplexed base editing at therapeutically relevant genomic loci in primary human T cells and primary human hematopoietic stem and progenitor cells. TadCBEs expand the utility of CBEs for precision gene editing.","abstract_license":"CC-BY (article license as recorded by Europe PMC; abstract reproduced unmodified apart from markup removal)","license":"CC-BY","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":[],"details":null,"provenance":"europepmc","attribution":"Abstract of \"Evolution of an adenine base editor into a small, efficient cytosine base editor with low off-target activity\" by Neugebauer ME, Hsu A, Arbab M et al., https://doi.org/10.1038/s41587-022-01533-6, used under its Creative Commons Attribution license (CC-BY); markup removed, otherwise unmodified.","topics":[{"slug":"gene-editing-therapies","name":"CRISPR & Gene-Editing Therapies","domain_slug":"medicine"}],"cited_in_dossiers":[]}