Precision genome editing in plants: state-of-the-art in CRISPR/Cas9-based genome engineering

Table 2 Cas9 orthologs and engineered Cas9 variants

Cas9 Nuclease	Origin	PAM	Notes	References	Application to plant genome editing
SpCas9	S. pyogenes	NGG		See reviews ex. [1, 3, 8]	+
NmCas9	N. meningitidis	NNNNGMTT		[50]	-
StCas9	S. thermophilus	NNAGAAW		[51, 52]	+
SaCas9	S. aureus	NNGRRT, NNNRRT		[52,53,54]	+
CjCas9	C.r jejuni	NNNNRYAC		[55]	-
FnCas9	F. novicida	No		[56, 57]	+
SpCas9-VQR	S. pyogenes	NGA	Altered PAM	[58,59,60,61]	+
SpCas9-EQR	S. pyogenes	NGAG	Altered PAM	[58, 62]	+
SpCas9-VRER	S. pyogenes	NGCG	Altered PAM	[58, 59]	+
SpCas9-NG	S. pyogenes	NG	Altered PAM	[63,64,65,66,67,68,69]	+
SpCas9-HF1	S. pyogenes	NGG	High fidelity	[70, 71]	+
eSpCas9	S. pyogenes	NGG	High fidelity	[71, 72]	+
HypaCas9	S. pyogenes	NGG	High fidelity	[73]	-
evoCas9	S. pyogenes	NGG	High fidelity	[74]	-
Sniper-Cas9	S. pyogenes	NGG	High fidelity	[75]	-
xCas9	S. pyogenes	NG, GAA, GAT	Altered PAM, high fidelity	[65,66,67,68, 76,77,78]	+