The single guide RNA forms hydrogen bonds with DNA, while Cas9 hydrolyzes phosphodiester bonds
Explanation:
The base pairing between nucleic acid strands (either DNA or RNA) is through hydrogen bonds between nucleotide bases. In DNA, Adenine always forms two hydrogen bonds with Thymine, while Guanine always forms three hydrogen bonds only with Cytosine. Moreover, adjacent nucleotides in the same strand are covalently linked by phosphodiester bonds (i.e., covalent bonds between the 5' phosphate group of one nucleotide and the 3'-OH group of another). The CRISPR/Cas9 genome editing systems make use of single-guide RNAs (sgRNAs) that interact with DNA through hydrogen bonds. These sgRNAs have perfect complementarity to the target DNAs in order to bind them. On the other hand, Cas9 is an enzyme that hydrolyzes phosphodiester bonds in both DNA strands very precisely and accurately by using a sgRNA complementary to a specific DNA sequence.
