biostudies-literatureWei YChina Agricultural Research SystemLocal grantsSci-Tech Innovation 2030 Key ProgramNational Natural Science Foundation of Chinae2304113https://www.ebi.ac.uk/biostudies/studies/S-EPMC10797475biostudies-literatureUnknown11(3)Mitochondrial base editing with DddA-derived cytosine base editor (DdCBE) is limited in the accessible target sequences and modest activity. Here, the optimized DdCBE tools is presented with improved editing activity and expanded C-to-T targeting scope by fusing DddA11 variant with different cytosine deaminases with single-strand DNA activity. Compared to previous DdCBE based on DddA11 variant alone, fusion of the activation-induced cytidine deaminase (AID) from Xenopus laevis not only permits cytosine editing of 5'-GC-3' sequence, but also elevates editing efficiency at 5'-TC-3', 5'-CC-3', and 5'-GC-3' targets by up to 25-, 10-, and 6-fold, respectively. Furthermore, the A-to-G editing efficiency is significantly improved by fusing the evolved DddA6 variant with TALE-linked deoxyadenosineAdvanced science (Weinheim, Baden-Wurttemberg, Germany)Enhanced C-To-T and A-To-G Base Editing in Mitochondrial DNA with Engineered DdCBE and TALED.PMC107974752022ZD0401401Z10130230062023ZD0405104322728482022GD-TSLD-46CARS‐39‐03CARS-39-0332301251Yang HXu KXu CZhang MZhou YWei YLi WHuang SGao PLi SJin MRen NChen YWang XYao FfalseEnhanced C-To-T and A-To-G Base Editing in Mitochondrial DNA with Engineered DdCBE and TALED.Mitochondrial base editing with DddA-derived cytosine base editor (DdCBE) is limited in the accessible target sequences and modest activity. Here, the optimized DdCBE tools is presented with improved editing activity and expanded C-to-T targeting scope by fusing DddA11 variant with different cytosine deaminases with single-strand DNA activity. Compared to previous DdCBE based on DddA11 variant alone, fusion of the activation-induced cytidine deaminase (AID) from Xenopus laevis not only permits cytosine editing of 5'-GC-3' sequence, but also elevates editing efficiency at 5'-TC-3', 5'-CC-3', and 5'-GC-3' targets by up to 25-, 10-, and 6-fold, respectively. Furthermore, the A-to-G editing efficiency is significantly improved by fusing the evolved DddA6 variant with TALE-linked deoxyadenosine2024-01-01T00:00:00Z2024 Jan2026-06-02T02:23:33.141Z2025-04-04T19:22:08.874ZS-EPMC107974753798486610.1002/advs.202304113