How is bacterial DNA methylation and expression of restriction enzymes an innate
ID: 263019 • Letter: H
Question
How is bacterial DNA methylation and expression of restriction enzymes an innate defense strategy, whereas the CRISPRICas system is an adaptive defense strategy? Select the two correct answers. CRISPR/Cas system cleaves CRISPR spacers in the genome since they contain bacteriophage sequences RISPR/Cas system cleaves complementary DNA sequences CRISPR loci transcribe crRNAs that guide nucleases to invading complementary DNAs in order to destroy foreign DNA. O O DNA methylation provides a defense against the integration of foreign DNA into the bacterial chromosome. DNA methylation allows to transcribe the inserted phage genomeExplanation / Answer
Ans-
CRISPR/Cas system cleaves complementary DNA sequences
CRISPR loci transcribe crRNAs that guide nucleases to invading complementary DNAs in order to destroy foreign DNA
Explanation:
CRISPR is present in the prokaryotic genome that produces complementary RNAs which bind target DNA sequences to destroy them. The crRNA (CRISPR RNA) and the tracrRNA (trans-activating crRNA) are fused to form a single guide RNA (sgRNA) where CRISPR loci transcribe crRNA that guide nucleases to invading complementary DNAs to destroy foreign DNA.