Final answer:
DNA polymerase processivity at the replication fork is increased by proteins like PCNA which keep the polymerase attached to DNA, while helicases and topoisomerases manage DNA unwinding and prevent over-winding.
Step-by-step explanation:
The processivity of DNA polymerases at the replication fork is dramatically increased by several mechanisms. A sliding clamp protein, known as the proliferating cell nuclear antigen (PCNA), encircles the DNA and binds to the polymerase, greatly increasing its affinity for the DNA template and preventing it from dissociating after adding each nucleotide. Helicases unwind the DNA helix, while topoisomerases prevent over-winding by causing temporary nicks in the DNA ahead of the replication fork and then resealing it. DNA polymerase α initiates synthesis with a short DNA fragment on the RNA primer, then hands off to pol ε for the leading strand or pol δ for the lagging strand. RNase H and DNA ligase work to remove RNA primers and join Okazaki fragments, respectively, ensuring a continuous strand.