Final answer:
Mismatch repair proteins recognize the newly synthesized strand by utilizing the difference in methylation patterns between the parental and daughter strands. After replication, the parental strand is methylated, while the daughter strand remains unmethylated. This allows the mismatch repair proteins to specifically target the newly synthesized strand for repair.
Step-by-step explanation:
Mismatch repair is a mechanism that corrects errors that occur during DNA replication. In order to recognize the newly synthesized strand and repair it, the mismatch repair proteins rely on methylation patterns. In E. coli, after replication, the nitrogenous base adenine acquires a methyl group on the parental strand, while the newly synthesized daughter strand remains unmethylated. This difference in methylation allows the proteins Muts, MutL, and MutH to bind to the hemimethylated site and identify the incorrect nucleotide on the newly synthesized strand. MutH then cuts the nonmethylated strand, and an exonuclease removes the incorrect nucleotide, creating a gap. The gap is then filled in by DNA polymerase III and sealed by DNA ligase.