What is the primary role of DNA polymerase I in DNA replication?

The primary role of DNA polymerase I in DNA replication is to replace RNA primers with DNA. During DNA replication, short RNA primers are synthesized to provide a starting point for DNA synthesis. DNA polymerase I has the specific task of removing these RNA primers and replacing them with the appropriate DNA nucleotides, thereby ensuring that the newly synthesized DNA strand is continuous and fully composed of DNA. This function is critical for the integrity of the newly formed DNA strands, as it allows for the accurate propagation of genetic information.

While other enzymes also play important roles in DNA replication—such as DNA polymerase III, which synthesizes the new DNA strands, and DNA ligase, which seals gaps between Okazaki fragments—the primary function of DNA polymerase I is focused on the replacement of RNA with DNA. This replacement is essential, as any remaining RNA could lead to problems in replication and stability of the DNA molecule.