Table 2.
Summary of SpCas9 variants for improving editing specificity.
| Variants | Year | Mutations | References |
|---|---|---|---|
| SpCas9 nickase 1 | 2013 | D10A or H840A | [25] |
| FokI-dCas9 1 | 2014 | D10A, H840A | [33,66] |
| SpCas9-D1135E | 2015 | D1135E | [27] |
| eSpCas9(1.0) | 2016 | K810A, K1003A, R1060A | [18] |
| eSpCas9(1.1) | 2016 | K848A, K1003A, R1060A | [18] |
| SpCas9-HF1 | 2016 | N497A, R661A, Q695A, Q926A | [26] |
| HypaCas9 | 2017 | N692A, M694A, Q695A, H698A | [21] |
| HiFi Cas9 | 2018 | R691A | [20] |
| xCas9-3.6 | 2018 | E108G, S217A, A262T, S409I, E480K, E543D, M694I, E1219V | [30] |
| xCas9-3.7 | 2018 | A262T, R324L, S409I, E480K, E543D, M694I, E1219V | [30] |
| Sniper-Cas9 | 2018 | F539S, M763I, K890N | [23] |
| evoCas9 | 2018 | M495V, Y515N, K526E, R661Q | [19] |
| SpartaCas | 2020 | D23A, T67L, Y128V, D1251G | [24] |
| LZ3 Cas9 2 | 2020 | N690C, T769I, G915M, N980K | [29] |
| miCas9 3 | 2020 | The brex27 motif fused to SpCas9 | [32] |
| SuperFi-Cas9 | 2022 | Y1010D, Y1013D, Y1016D, V1018D, R1019D, Q1027D, K1031D | [28] |
1 For SpCas9 nickase and FokI-dCas9, the Cas9 variants are used in pairs to increase gene-editing specificity. 2 The amino acid substitutions in LZ3 Cas9 are not explicitly described in the original paper by Schmid-Burgk et al. We collected the mutations from the deposited plasmid (https://www.addgene.org/140561/) (accessed on 8 June 2022). 3 miCas9 improves gene-editing specificity not through reducing non-specific recognition between gRNA and target DNA site but rather through enhanced homology-directed repair.