During DNA replication, some enzymes and proteins join near the replication fork to form complex molecular structures. It is called replisome or replication complex. The main components of replisome are-
1. DNA Helicase: The DNA helicase enzyme unwinds the DNA double helix at the replication fork.
2. DNA Polymerase: DNA polymerase enzyme joins nucleotides to form a complementary strand directed 5→3. DNA proof reading.
3. Topo-Isomerase: Topo-isomerase enzyme frees DNA from super coiled state.
4. DNA Clumps: DNA clumps inhibit maternal elongation of DNA.
5. DNA gyrase: The enzyme DNA gyrase creates supercoils (coils) at the end of DNA replication.
6. DNA ligase: The enzyme DNA ligase joins the Okazaki fragment to the complementary strand. Stops chain DNA sequence elongation.
7. SSBP: Single Strand Binding Proteins (SSBP) prevent single strand DNA molecules from refolding back into the double helix state.
8. Primase: Primase enzyme joins the RNA primer to the ends of the chain.
9. Telomerase: The telomerase enzyme adds nucleotides to telomeric DNA-molecules in eukaryotic chromosomes.
10. Exonuclease: Exonuclease enzyme removes the primers from the chain.
11. Nuclease: Nuclease enzymes remove incorrect nucleotides from complementary primers or strands.