Question
5-methyl cytosine mutation of DNA (DNA methylation) leads to:
A. Deamination to thiamine;
B. DNA repair
C. Methylation protects the host DNA from cleavage by its own restriction enzyme
D. All
Show Answer
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Correct Answer » D Explanation |
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Deamination of cytosine forms uracil and deamination of 5 methylcytosine forms thymine. TDG & MBD4 DNA uracil glycosylase removes either U or T residues paired with G, generated by deamination.
DNA methylation of adenine at 5′ GATC repair mismatched base pairs. And methylated parental (template) strand is protected from cleavage/digestion by its own restriction enzyme.