Which enzyme removes the RNA primer and replaces it with DNA nucleotides?

The function of removing the RNA primer and replacing it with DNA nucleotides is specifically carried out by DNA polymerase I. This enzyme plays a critical role during DNA replication, particularly in the synthesis of the lagging strand.

During replication, short RNA primers are synthesized to initiate the process of building new DNA strands. Once the synthesis has progressed, DNA polymerase I comes into action. It recognizes and binds to the RNA primers, removes them, and fills in the gaps with DNA nucleotides, ensuring the continuity and integrity of the new DNA strand.

This enzymatic action is essential for maintaining the accuracy of DNA replication. In contrast, primase is responsible for synthesizing the RNA primers, helicase unwinds the DNA double helix, and DNA ligase joins the Okazaki fragments on the lagging strand, sealing the nicks after the RNA primer has been replaced. Each of these enzymes has distinct roles, with DNA polymerase I being the specific enzyme tasked with the replacement of RNA primers with DNA.