Engineered CRISPR-Cas9 nucleases with altered PAM specificity
Engineered CRISPR-Cas9 nucleases with altered and improved PAM specificities and their use in genomic engineering, epigenomic engineering, and genome targeting.
1. A Streptococcus pyogenes Cas9 (SpCas9) protein, comprising an amino acid sequence that has at least 80% sequence identity to the amino acid sequence of SEQ ID NO: 1, with mutations at positions: D1135, 51136, and G1218, wherein the mutation at D1135 is M, the mutation at 51136 is Q, and the mutation at G1218 is K.
2. The SpCas9 protein of claim 1 , further comprising a mutation at position E1219.
3. The SpCas9 protein of claim 2 , wherein the mutation at position E1219 is S or F.
4. The SpCas9 protein of claim 1 , further comprising:
(i) a mutation at a position selected from the group consisting of D10, E762, D839, H983, and D986; and/or
(ii) a mutation at position H840 or N863.
5. The SpCas9 protein of claim 4 , wherein the mutations are:
(i) D10A or D10N, and/or
(ii) H840A, H840N, or H840Y.
6. The SpCas9 protein of claim 1 , wherein the protein comprises one or more of a nuclear localization sequence, cell penetrating peptide sequence, and/or affinity tag.
7. A fusion protein comprising the SrCas9 protein of claim 1 , fused to a heterologous functional domain.
8. The fusion protein of claim 7 , wherein the heterologous functional domain is a transcriptional activation domain.
9. The fusion protein of claim 8 , wherein the transcriptional activation domain is VP16, VP64, rTA, NF-KB p65, or the composite VPR (VP64-p65-rTA).
10. The fusion protein of claim 7 , wherein the heterologous functional domain is a transcriptional silencer or transcriptional repression domain.
11. The fusion protein of claim 10 , wherein the transcriptional repression domain is a Krueppel-associated box (KRAB) domain, ERF repressor domain (ERD), or mSin3A interaction domain (SID).
12. The fusion protein of claim 10 , wherein the transcriptional silencer is Heterochromatin Protein 1 (HP1).
13. The fusion protein of claim 7 , wherein the heterologous functional domain is an enzyme that modifies the methylation state of DNA.
14. The fusion protein of claim 13 , wherein the enzyme that modifies the methylation state of DNA is a DNA methyltransferase (DNMT) or a TET protein.
15. The fusion protein of claim 7 , wherein the heterologous functional domain is an enzyme that modifies a histone subunit.
16. The fusion protein of claim 15 , wherein the enzyme that modifies a histone subunit is a histone acetyltransferase (HAT), histone deacetylase (HDAC), histone methyltransferase (HMT), or histone demethylase.
17. The fusion protein of claim 7 , wherein the heterologous functional domain is a base editor.
18. The fusion protein of claim 7 , wherein the heterologous functional domain is (i) a cytidine deaminase domain, or (ii) an adenosine deaminase.
19. The fusion protein of claim 18 , wherein the heterologous functional domain is a cytidine deaminase domain selected from the group consisting of apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like (APOBEC) deaminase; activation-induced cytidine deaminase (AID); and cytosine deaminase acting on tRNA (CDAT).
20. The fusion protein of claim 18 , wherein the heterologous functional domain is an adenosine deaminase and selected from the group consisting of adenosine deaminase 1 (ADA1), ADA2; adenosine deaminase acting on RNA 1 (ADAR1), ADAR2, ADAR3; adenosine deaminase acting on tRNA 1 (ADAT1), ADAT2, ADAT3; and naturally occurring or engineered tRNA-specific adenosine deaminase (TadA).
21. A method of editing a nucleotide base in a double stranded DNA (dsDNA) molecule, the method comprising contacting the dsDNA molecule with the fusion protein of claim 18 , and a guide RNA having a region complementary to a selected portion of the dsDNA molecule.
22. The method of claim 21 , wherein the heterologous functional domain is a cytidine deaminase domain selected from the group consisting of apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like (APOBEC) deaminase; activation-induced cytidine deaminase (AID); and cytosine deaminase acting on tRNA (CDAT).
23. The method of claim 21 , wherein the heterologous functional domain is an adenosine deaminase selected from the group consisting of adenosine deaminase 1 (ADA1), ADA2; adenosine deaminase acting on RNA 1 (ADAR1), ADAR2, ADAR3; adenosine deaminase acting on tRNA 1 (ADAT1), ADAT2, ADAT3; and naturally occurring or engineered tRNA-specific adenosine deaminase (TadA).
24. A method of altering the genome of a cell, the method comprising expressing in the cell, or contacting the cell with, the protein of claim 1 , and a guide RNA having a region complementary to a selected portion of the genome of the cell.
25. A method of altering a double stranded DNA (dsDNA) molecule, the method comprising contacting the dsDNA molecule with the protein of claim 1 , and a guide RNA having a region complementary to a selected portion of the dsDNA molecule.
26. The SpCas9 protein of claim 1 , further comprising a mutation at position R1335.
27. The SpCas9 protein of claim 1 , further comprising a mutation at position T1337.
28. The SpCas9 protein of claim 1 , further comprising a mutation at position E1219, a mutation at position R1335, and a mutation at position T1337.
29. The SpCas9 protein of claim 28 , wherein the mutation at position E1219 is S or F, the mutation at position R1335 is E, and the mutation at position T1337 is R.
30. The SpCas9 protein of claim 1 , wherein the amino acid sequence has at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 1.
31. The SpCas9 protein of claim 1 , wherein the amino acid sequence has at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 1.