Fig. 2

Modified nuclease systems to bias HDR at specific DSBs. A Schematic of HDR factors tethered to Cas9 via peptide linker can promote strand-invasion (Cas9-yRAD2, Cas9-Brex27), end-resection (Cas9-CtIP, Cas9-MRE11, Cas9-UL12), or single-strand annealing (Cas9-RecA) at a DNA double-strand break. B Diagram of the REDIT system composed of Cas9, sgRNA, RNA aptamer with MS2 loop, MS2 coat protein (MCP), RecT, and either single-strand DNA (ssDNA) or double-stranded DNA (dsDNA) donors. C Visual representation of Cas9-hGem levels during cell cycle stages and Cas9-hGem construct. D Overview of S1mplex components: Cas9, sgRNA, RNA aptamer, streptavidin, biotin, and either ssDNA or dsDNA donors. E Cas9 tethered to PCV, an HUH endonuclease forming a covalent bond with ssODN donor. F A transcription factor DNA binding domain fused to Cas9 with a peptide linker binding to motifs presents donor DNA