Type III-A CRISPR/Cas10 system ofmycobacteria
A. Type III-A CRISPR/Cas10 system in M. tuberculosis, M. bovis, and M. avium. * indicates that the CRISPR locus 2 of the M. avium CRISPR system is characterized. B. Schematic shows crRNA biogenesis by the type III-A CRISPR crRNP complex. This crRNP complex then cleaves DNA through a transcription-dependent process and RNA through a transcription-independent process. C. Expression of csm3, csm6, and cas10 in M. tuberculosis detected by qRT-PCR. D.–F. qRT-PCR identification of the expression of csm3, csm6, and cas10 in strains transformed with the mini-CRISPR array (containing gRNA) and empty vector (control), respectively. –(RT) indicates a negative control to ensure that no genomic DNA contamination occurred. Student’s t-test (***, P < 0.001). R, repeat; S, spacer; crRNP, crRNA ribonucleoprotein.