DNA base editor (CRISPR-guided deaminase fusion protein) (Base editor (BE); specific versions include cytosine base editor (CBE) and adenine base editor (ABE))

DNA base editors are engineered fusion proteins combining a catalytically impaired CRISPR-associated nuclease (commonly Cas9) with a single-stranded DNA deaminase enzyme, capable of introducing precise, programmable nucleotide substitutions at specific genomic loci without creating double-stranded DNA breaks[1][3][5][7]. The system uses a guide RNA to direct the fusion protein to the target DNA sequence, where the deaminase catalyzes conversion of cytosine to uracil (in cytosine base editors) or adenine to inosine (in adenine base editors); these modifications are recognized and fixed as C→T or A→G transitions by cellular repair pathways[3][5][7]. Such tools are research and medical candidates for correcting pathogenic point mutations in living cells and tissues, with advantages in efficiency and precision but significant ongoing concerns regarding specificity and safety.

Other names

CRISPR base editorCytosine base editor (CBE)Adenine base editor (ABE)Cas9-deaminase fusion proteinCRISPR-guided base editor

Induces targeted chemical conversion of a single nucleotide (C→T or A→G) in genomic DNA through RNA-guided binding and enzymatic deamination[3][5][7]