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Fig. 6.1 Mechanism of CRISPR-Cas system inside a bacterium. Step1 Spacer aquisition:
Spacer DNA of phage integrates with CRISPR locus, the CRISPR locus comprises spacer
sequences of previous invaders and into pre crRNA. This pre-crRNA and trac RNA form a long
RNA binate. Step 2 The RNA binate is severed by RNAase III into small units. Step3 RNA binates
forms a multiplex with Cas9 protein. Step 4 Guide RNA identifies the PAM sequence present near
target sequence (phage DNA). The CRISPR-Cas9 machinery severs the DNA at the target site
A. P. Sarma et al.
Fig. 6.1 Mechanism of CRISPR-Cas system inside a bacterium. Step1 Spacer aquisition:
Spacer DNA of phage integrates with CRISPR locus, the CRISPR locus comprises spacer
sequences of previous invaders and into pre crRNA. This pre-crRNA and trac RNA form a long
RNA binate. Step 2 The RNA binate is severed by RNAase III into small units. Step3 RNA binates
forms a multiplex with Cas9 protein. Step 4 Guide RNA identifies the PAM sequence present near
target sequence (phage DNA). The CRISPR-Cas9 machinery severs the DNA at the target site
A. P. Sarma et al.