Question

What is the rate-limiting step in the processes of DNA replication and DNA transcription?  

Answer 1

Please find the answers below:

1. Rate limiting step in DNA replication: During DNA replication, the DNA polymerase binds to the template strand of the double helix by appropriate identification of the template and non-template strand. This step is the rate limiting step of DNA replication initiation and the whole process and holds true for both leading and lagging strands. Failure of binding of the DNA polymerase to template strand or faulty binding can both lead to drastic down-regulation in the processivity of DNA replication.

2. Rate limiting step in trasncription: There are many rate limiting steps in the process of transcription. Out of all, the binding of RNA polymerase to template DNA remains one of the most critical and rate limiting event. Further, during elongation of transcription, the phosphorylation of C-terminal domain of the transcription elongation factor II remains the rate limiting step which can immediately halt the whole process if remains un-phosphorylated at the serine residues.

Thus, rate limiting steps in these biological process are highly critical for determination of fidelity and processivity.