. 2022 Jan 29;65(2):146–161. doi: 10.1007/s12033-021-00431-7

Table 1.

Applied types of class II CRISPR–Cas system

Type	Subtypes	Nuclease domain	PAM/PFS	Cleavage activity	Applications
II (Cas9)	II-A II-B II-C	HNH and RuvC domains	3′ G-rich motif	dsDNA blunt cleavage activity	Diagnostic platforms Genome-wide screening Animal model designing
V (Cas12)	V-A (Cas12a/Cpf1)	RuvC and Nuc domains	5′ T-rich motif	dsDNA overhang cleavage activity and ssDNA collateral cleavage activity	Diagnostic platforms
V (Cas12)	V-B (Cas12b/C2c1)	RuvC domain	5′ T-rich motif		Diagnostic platforms
VI (Cas13)	VI-A (Cas13a/C2c2)	2 HEPN domains	3′ none G PFS	ssRNA overhang cleavage activity and ssRNA collateral cleavage activity	Diagnostic platforms Anti-viral therapy
VI (Cas13)	VI-D (Cas13d)	2 HEPN domains	None		Diagnostic platforms Anti-viral therapy

PAM protospacer adjacent motif, PFS protospacer flanking site