Table 6.1 Subsets of CRISPR-Cas system
Types
I
II
III
IV
V
VI
Class
1
2
1
1
2
2
Signature
gene
Cas3
Cas9
Cas10
csf1
Cas12a (Cpf1)
Cas13
Functions
of signature
genes
Helicase activity;
nuclease activity;
degradation of invader
DNA
crRNA biogenesis;
cleavage of invader DNA
Role in nucleic acid
(target) interference
Utilize crRNA;
generation of crRNA
directly from alien
RNA
Combines the interference
module with adaptor
module
The encoded protein
binds and cleaves
RNA
Subtypes
I-A, I-B, I-C, I-U, I-D,
I-E, I-F, I-F variant
II-A, II-B, II-C, II-C
variant
III-A, III-B, III-C, III-D
IV-A, IV-B
V-A, V-B, V-B variant,
V-C, V-D, V-E, V-U, V-U1,
V-U2, V-U3, V-U4, V-U5
VI-A, VI-B1, VI-B2,
VI-C, VI-D
Bacterial
species
Archaeglobus fulgidus,
Clostridium kluyveri,
Bacillus halodurans,
Geobactersulfurreducens,
Cyanothecesp
8802, E.
coli
K12, Yersinia
pseudotuberculosis,
Shewanella putrefaciens
CN-32
Streptococcus
thermophilus, L.
pneumophila, N.
lactamica,
Micrarchaeumacidiphilum
ARMAN-1
Staphylococcus epidermidis,
Synechocystis sp.
6803,
Methanothermobacter
thermautotrophicus,
Pyrococcusfuriosus
Thioalkalivibrio sp.
K90mix,
Rhodococcus jostii
RHA1
Francisella cf. novicida
Fx1, Alicyclobacillus
acidoterrestris,
Planctomycetes bacterium
RBG_13_48_10,
Bacterium
CG09_39_24,
Gordonia sp., Cyanothece
sp.
PCC 8801, Bacillus
thuringiensis
HD-771,
Rothiadentocariosa
M567,
Leptotrichia shahii,
Ruminococcus
bicirculans,
Fusobacterium
perfoetens,
Prevotellabuccae,
Bergeyellazoohelcum
References Nuñez et al. (2014), Makarova and Koonin (2015), Makarova et al. (2015), Abudayyeh et al. (2016), Koonin et al. (2017), Karimi et al. (2018), and
McDonald et al. (2019)