Fig. 2
From: CRISPR-Based Diagnosis of Infectious and Noninfectious Diseases
Biology of the CRISPR-Cas system. a Formation of CRISPR array occurs during adaptation process in which after injection of invader genome into the host cell, some Cas proteins like Cas1 and Cas2 recognize the protospacer sequence (green rectangle) and cut it and integrate it into host genome in CRISPR loci. b In crRNA maturation, a pre-crRNA is transcribed and Cas6 proteins attach to the 3′ end of repeat segments and cut the 5′ end of spacer fragments to construct the mature crRNA. In the interference process the mature crRNA-Cas protein complex recognizes and cuts the complementary sequence on the phage genome