biostudies-literatureUnknown21(1)Zhao D<h4>Background</h4>Nme2ABE8e has been constructed and characterized as a compact, accurate adenine base editor with a less restrictive dinucleotide protospacer-adjacent motif (PAM: N4CC) but low editing efficiency at challenging loci in human cells. Here, we engineered a subset of domain-inlaid Nme2Cas9 base editors to bring the deaminase domain closer to the nontarget strand to improve editing efficiency.<h4>Results</h4>Our results demonstrated that Nme2ABE8e-797 with adenine deaminase inserted between amino acids 797 and 798 has a significantly increased editing efficiency with a wide editing window ranging from 4 to 18 bases in mammalian cells, especially at the sites that were difficult to edit by Nme2ABE8e. In addition, by swapping the PAM-interacting domain of Nme2ABE8e-797 with thatBMC biology250https://www.ebi.ac.uk/biostudies/studies/S-EPMC10636962biostudies-literatureEngineered domain-inlaid Nme2Cas9 adenine base editors with increased on-target DNA editing and targeting scope.PMC10636962Li JQian YZhang TLi ZWang DHu MZhao DGao XLai LNiu WZhou JXiong HfalseEngineered domain-inlaid Nme2Cas9 adenine base editors with increased on-target DNA editing and targeting scope.<h4>Background</h4>Nme2ABE8e has been constructed and characterized as a compact, accurate adenine base editor with a less restrictive dinucleotide protospacer-adjacent motif (PAM: N4CC) but low editing efficiency at challenging loci in human cells. Here, we engineered a subset of domain-inlaid Nme2Cas9 base editors to bring the deaminase domain closer to the nontarget strand to improve editing efficiency.<h4>Results</h4>Our results demonstrated that Nme2ABE8e-797 with adenine deaminase inserted between amino acids 797 and 798 has a significantly increased editing efficiency with a wide editing window ranging from 4 to 18 bases in mammalian cells, especially at the sites that were difficult to edit by Nme2ABE8e. In addition, by swapping the PAM-interacting domain of Nme2ABE8e-797 with that2023-01-01T00:00:00Z2023 Nov2026-05-28T15:24:41.549Z2025-02-18T23:30:34.565ZS-EPMC106369623794620010.1186/s12915-023-01754-4