Question

Mismatch repair requires the ability to distinguish between template and newly synthesized DNA strands. How can E. coli distinguish between these two strands?

a. Template DNA is methylated.
b. New DNA is methylated.
c. Template DNA is phosphorylated.
d. New DNA is phosphorylated.
e. New DNA contains single-stranded binding proteins

Answer 1

In E. coli, template and newly synthesized DNA strands are distinguished based on methylation patterns. The parental DNA strand is methylated, while the newly synthesized daughter strand is not. Proteins Muts, MutL, and MutH are involved in the mismatch repair process.

Step-by-step explanation:

In E. coli, the mismatch repair mechanism distinguishes between template and newly synthesized DNA strands based on methylation patterns. The parental DNA strand is methylated, while the newly synthesized daughter strand is not. It takes some time for the new strand to be methylated. Proteins Muts, MutL, and MutH bind to the hemimethylated site where the incorrect nucleotide is found. MutH cuts the non-methylated strand (the new strand), and the gap formed is then filled in by DNA pol III and ligase.