CRISPR–Cas9 a boon or bane: the bumpy road ahead to cancer therapeutics

Table 1 Cas9 proteins and their function in CRISPR editing

Cas protein	CRISPR system	Guide RNA	Nuclease activity	Recognition sequence on target	Reference
Cas9	Type II	crRNA + transcrRNA	Yes	G-rich PAM	[49, 50]
Cpf1	Type V	crRNA	Yes	G-rich PAM	[46]
Cas13a	Type VI-A	crRNA + transcrRNA	Yes	Except G-rich	[54]
dCas9	Type II	crRNA + transcrRNA	No	G-rich PAM	[140]
Cas3	Type I	crRNA	Yes	T-rich PAM	[141, 142]
Cas10/Csm1	Type III	crRNA	Yes	AT-rich PAM	[143, 144]
dCas13a	Type VI-A	crRNA + transcrRNA	Yes	Except G-rich	[145]

ISSN: 1475-2867