Question

How is proofreading of a newly replicated section of DNA accomplished?

Answer 1

Dna replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. it is a highly accurate process, but mistakes can occasionally occur, such as a DNA polymerase inserting a wrong base. Repair mechanisms correct the mistakes.Most of the mistakes during DNA replication are promptly corrected by DNA polymerase by proofreading the base that has been just added . In proofreading, the DNA pol reads the newly added base before adding the next one, so a correction can be made. Then The polymerase checks whether the newly added base has paired correctly with the base in the template strand. If it is the right base, the next nucleotide is added. If an incorrect base has been added, the enzyme makes a cut at the phosphodiester bond and releases the wrong nucleotide. This is performed by the exonuclease action of DNA pol III. Once the incorrect nucleotide has been removed, a new one will be added again.