Table 1 Open in new tab General...

Class	Type	Subtype	Signature Gene	Target	crRNA	Representative Cas Proteins Related to Each Step
I	Type I	7	cas3	DNA	Single crRNA	Cas6	Cas5, Cas7,Cas8, Cas11	Cas3
	(d^b)	cas3	DNA	Single crRNA	Cas6	Cas5, Cas7	Cas10
I	Type III	6	cas10	DNA/RNA	Single crRNA	Cas6	Cas5, Cas7, Cas11, Cas10	Cas10
I	Type IV	3	csf1^c	–	–	Cas6	Cas5, Cas7, Cas11, Csf1
II	Type II	3	cas9	DNA	tracrRNA:crRNA	Cas9, RNase III	Cas9	Cas9
II	Type V	10	cas12	DNA	Single crRNA/tracrRNA:crRNA	Cas12	Cas12	Cas12
II	Type VI	4	cas13	RNA	Single crRNA	Cas13	Cas13	Cas13

Class	Type	Subtype	Signature Gene	Target	crRNA	Representative Cas Proteins Related to Each Step
I	Type I	7	cas3	DNA	Single crRNA	Cas6	Cas5, Cas7,Cas8, Cas11	Cas3
	(d^b)	cas3	DNA	Single crRNA	Cas6	Cas5, Cas7	Cas10
I	Type III	6	cas10	DNA/RNA	Single crRNA	Cas6	Cas5, Cas7, Cas11, Cas10	Cas10
I	Type IV	3	csf1^c	–	–	Cas6	Cas5, Cas7, Cas11, Csf1
II	Type II	3	cas9	DNA	tracrRNA:crRNA	Cas9, RNase III	Cas9	Cas9
II	Type V	10	cas12	DNA	Single crRNA/tracrRNA:crRNA	Cas12	Cas12	Cas12
II	Type VI	4	cas13	RNA	Single crRNA	Cas13	Cas13	Cas13

Table 1

General characteristics of each type of CRISPR–Cas system^a

Class	Type	Subtype	Signature Gene	Target	crRNA	Representative Cas Proteins Related to Each Step
Class	Type	Subtype	Signature Gene	Target	crRNA	RNA Processing	Target Binding	Target Cleavage
I	Type I	7	cas3	DNA	Single crRNA	Cas6	Cas5, Cas7,Cas8, Cas11	Cas3
I		(d^b)	cas3	DNA	Single crRNA	Cas6	Cas5, Cas7	Cas10
I	Type III	6	cas10	DNA/RNA	Single crRNA	Cas6	Cas5, Cas7, Cas11, Cas10	Cas10
I	Type IV	3	csf1^c	–	–	Cas6	Cas5, Cas7, Cas11, Csf1
II	Type II	3	cas9	DNA	tracrRNA:crRNA	Cas9, RNase III	Cas9	Cas9
II	Type V	10	cas12	DNA	Single crRNA/tracrRNA:crRNA	Cas12	Cas12	Cas12
II	Type VI	4	cas13	RNA	Single crRNA	Cas13	Cas13	Cas13

Class	Type	Subtype	Signature Gene	Target	crRNA	Representative Cas Proteins Related to Each Step
Class	Type	Subtype	Signature Gene	Target	crRNA	RNA Processing	Target Binding	Target Cleavage
I	Type I	7	cas3	DNA	Single crRNA	Cas6	Cas5, Cas7,Cas8, Cas11	Cas3
I		(d^b)	cas3	DNA	Single crRNA	Cas6	Cas5, Cas7	Cas10
I	Type III	6	cas10	DNA/RNA	Single crRNA	Cas6	Cas5, Cas7, Cas11, Cas10	Cas10
I	Type IV	3	csf1^c	–	–	Cas6	Cas5, Cas7, Cas11, Csf1
II	Type II	3	cas9	DNA	tracrRNA:crRNA	Cas9, RNase III	Cas9	Cas9
II	Type V	10	cas12	DNA	Single crRNA/tracrRNA:crRNA	Cas12	Cas12	Cas12
II	Type VI	4	cas13	RNA	Single crRNA	Cas13	Cas13	Cas13

Classification is based on Makarova et al. (2020).

A cas3 gene is present as a signature gene in type I-D but cleavage is performed by Cas10, not Cas3.

Some type IV CRISPR–Cas systems lack a csf1 gene.