Table 2.

Different newly emerged CRISPR/Cas techniques with potential functions in associated hosts.

Class Name	Size(AA)	PAM	Host	Spacer (bp)	Cut Site	Target	Ref
AacC2c1	1277	T-rich PAM	Alicyclobacillus acidoterrestris	20	Upstream of PAM	Ds DNA	[79]
CjCas9	984	NNNNACAC and NNNRYAC	Campylobacter jejuni	22	Upstream of PAM	DsDNA	[80]
Cpf1	–	TTTV	Prevotella & Francisella 1	20	Downstream of PAM	DsDNA	[67]
Cpf1(AsCpf1)	1307	5′-TTTN-3′	Acidaminococcus sp.	24	Downstream of PAM	DsDNA	[81]
Cas12a	-	Thymine-rich PAM sequences	Acidaminococcus sp.	-	Downstream of PAM	Ds DNA	[69]
Cas13	1440	Non-G nucleotide at the 3′	orthologs; Leptotrichia shaii	28	-	ssRNA	[82]
Cas14	400–700	-	Uncultivated archaea	-	-	ssDNA	[71]
FnCas9	1629	5′-NGG-3′	Francisella novicida	20	Upstream of PAM	Ds DNA	[83]
Nme Cas9	1082	5′ NNNNGATT-3′	Neisseria meningitidis	24 and 20	Upstream of PAM	DsDNA	[84]
SaCas9	1053	5ʹ-NNGRRT-3′	Staphylococcus aureus	21	Upstream of PAM	DsDNA	[85]
SpCas9	1368	5′-NGG-3′	Streptococcus pyogenes	-	Upstream of PAM	DsDNA	[31]
SpCas9-NG–	-	5′-NAC, NTG, NTT, and NCG	S. pyogenes	-	Upstream of PAM	DsDNA	[86]
St1Cas9	1121	NNAGAAW	Streptococcus thermophilus	20	Upstream of PAM	DsDNA	[87]
St3Cas9	1409	5′-NGGNG-3′	S. thermophilus	20	Upstream of PAM	DsDNA	[56]
xCas9	–	GAA, GAT and NG	-	19–22	Upstream of PAM	DsDNA	[88]

‘–’: information unavailable.