Patent
This invention pertains to mutant Cas9 nucleic acids and proteins for use in CRISPR/Cas endonuclease systems, and their methods of use. In particular, the invention pertains to an isolated mutant Cas9 protein, wherein the isolated mutant Cas9 protein is active in a CRISPR/Cas endonuclease system, wherein the CRISPR/Cas endonuclease system displays reduced off-target editing activity and maintained on-target editing activity relative to a wild-type CRISPR/Cas endonuclease system. The invention also includes isolated nucleic acids encoding mutant Cas9 proteins, ribonucleoprotein complexes and CRSPR/Cas endonuclease systems having mutant Cas9 proteins that display reduced off-target editing activity and maintained on-target editing activity relative to a wild-type CRISPR/Cas endonuclease system.
1. An isolated mutant Cas9 protein having activity in a CRISPR/Cas endonuclease system, wherein the CRISPR/Cas endonuclease system displays reduced off-target editing activity and maintains on-target editing activity relative to a wild-type CRISPR/Cas endonuclease system having the wild-type Cas9 protein of SEQ ID NO: 5, wherein the isolated mutant Cas9 protein consists of a substitution mutation selected from the group consisting of
(a) a single substitution mutation introduced into the WT-Cas9 protein of SEQ ID NO: 5 selected from the following positions: R494, N522, N588, N612, T657, S663, R691, N692, 5730, T740, R765, T770, N776, S793, N803, N854, 5872 and R925; or
(b) a double substitution mutation introduced into the WT-Cas9 protein of SEQ ID NO: 5 selected from two of following positions: R494, N522, N588, N612, T657, S663, R691, N692, 5730, T740, R765, T770, N776, R778, R783, S793, N803, 5845, N854, S872 and R925.
2. The isolated mutant Cas9 protein of claim 1 , wherein the isolated mutant Cas9 protein consists of a substitution mutation selected from the group consisting of a double substitution mutation introduced into the WT-Cas9 protein of SEQ ID NO: 5 selected from two of following positions: R494C or R494A; N522K or N522A; N588D or N588A; N612A; T657A; S663A; R691S or R691A; N692D or N692A; S730G or S730A; T740A; R765G or R765A; T770K or T770A; N776A; R778A; R783A; S793A; N803D or N803A; S845A; N854K or N854A; S872A; and R925C or R925A.
3. The isolated mutant Cas9 protein of claim 1 , wherein the isolated mutant Cas9 protein is selected from the group consisting of SEQ ID NO: 7-27, 30-32 and 34-38.
4. The isolated mutant Cas9 protein of claim 1 , wherein the isolated mutant Cas9 protein is selected from the group consisting of SEQ ID NO: 39-88.
5. A method of performing gene editing having reduced off-target editing activity and/or increased on-target editing activity, comprising:
contacting a candidate editing target site locus with an active CRISPR/Cas endonuclease system having a mutant Cas9 protein, wherein the active CRISPR/Cas endonuclease system displays reduced off-target editing activity and maintained on-target editing activity relative to a wild-type CRISPR/Cas endonuclease system having the wild-type Cas9 protein of SEQ ID NO:5,
wherein the mutant Cas9 protein consists of a substitution mutation selected from the group consisting of
(a) a single substitution mutation introduced into the WT-Cas9 protein of SEQ ID NO: 5 selected from the following positions: R494, N522, N588, N612, T657, S663, R691, N692, 5730, T740, R765, T770, N776, 5793, N803, N854, 5872 and R925: or
(b) a double substitution mutation introduced into the WT-Cas9 protein of SEQ ID NO: 5 selected from two of following positions: R494, N522, N588, N612, T657, 5663, R691, N692, 5730, T740, R765, T770, N776, R778, R783, 5793, N803, 5845, N854, 5872 and R925.
6. The method of claim 5 , wherein the mutant Cas9 protein consists of a substitution mutation selected from the group consisting of a double substitution mutation introduced into the WT-Cas9 protein of SEQ ID NO: 5 selected from two of following positions R494C or R494A; N522K or N522A; N588D or N588A; N612A; T657A; S663A; R691A; N692D or N692A; S730G or S730A; T740A; R765G or R765A; T770K or T770A; N776A; R778A; R783A; S793A; N803D or N803A; S845A; N854K or N854A; S872A; and R925C or R925A.
7. The method of claim 5 , wherein the mutant Cas9 protein is selected from the group consisting of SEQ ID NO: 7-27, 30-32 and 34-38.
8. The method of claim 5 , wherein the mutant Cas9 protein is selected from the group consisting of SEQ ID NO: 39-88.
9. The method of claim 5 , wherein the isolated mutant Cas9 protein consists of a substitution mutation selected from the group consisting of a single substitution mutation introduced into the WT-Cas9 protein of SEQ ID NO: 5 selected from one of the following positions: R494, N522, N588, N612, T657, 5663, R691, N692, 5730, T740, R765, T770, N776, 5793, N803, N854, 5872 and R925.
10. The isolated mutant Cas9 protein of claim 1 , wherein the isolated mutant Cas9 protein consists of a substitution mutation selected from the group consisting of a single substitution mutation introduced into the WT-Cas9 protein of SEQ ID NO: 5 selected from one of the following positions: R494, N522, N588, N612, T657, S663, R691, N692, S730, T740, R765, T770, N776, S793, N803, N854, S872 and R925.