<P> Clamp proteins form a sliding clamp around DNA, helping the DNA polymerase maintain contact with its template, thereby assisting with processivity . The inner face of the clamp enables DNA to be threaded through it . Once the polymerase reaches the end of the template or detects double - stranded DNA, the sliding clamp undergoes a conformational change that releases the DNA polymerase . Clamp - loading proteins are used to initially load the clamp, recognizing the junction between template and RNA primers . </P> <P> At the replication fork, many replication enzymes assemble on the DNA into a complex molecular machine called the replisome . The following is a list of major DNA replication enzymes that participate in the replisome: </P> <Table> <Tr> <Th> Enzyme </Th> <Th> Function in DNA replication </Th> </Tr> <Tr> <Td> DNA Helicase </Td> <Td> Also known as helix destabilizing enzyme . Helicase separates the two strands of DNA at the Replication Fork behind the topoisomerase . </Td> </Tr> <Tr> <Td> DNA Polymerase </Td> <Td> The enzyme responsible for catalyzing the addition of nucleotide substrates to DNA in the 5' to 3' direction during DNA replication . Also performs proof - reading and error correction . There exist many different types of DNA Polymerase, each of which perform different functions in different types of cells . </Td> </Tr> <Tr> <Td> DNA clamp </Td> <Td> A protein which prevents elongating DNA polymerases from dissociating from the DNA parent strand . </Td> </Tr> <Tr> <Td> Single - Strand Binding (SSB) Proteins </Td> <Td> Bind to ssDNA and prevent the DNA double helix from re-annealing after DNA helicase unwinds it, thus maintaining the strand separation, and facilitating the synthesis of the nascent strand . </Td> </Tr> <Tr> <Td> Topoisomerase </Td> <Td> Relaxes the DNA from its super-coiled nature . </Td> </Tr> <Tr> <Td> DNA Gyrase </Td> <Td> Relieves strain of unwinding by DNA helicase; this is a specific type of topoisomerase </Td> </Tr> <Tr> <Td> DNA Ligase </Td> <Td> Re-anneals the semi-conservative strands and joins Okazaki Fragments of the lagging strand . </Td> </Tr> <Tr> <Td> Primase </Td> <Td> Provides a starting point of RNA (or DNA) for DNA polymerase to begin synthesis of the new DNA strand . </Td> </Tr> <Tr> <Td> Telomerase </Td> <Td> Lengthens telomeric DNA by adding repetitive nucleotide sequences to the ends of eukaryotic chromosomes . This allows germ cells and stem cells to avoid the Hayflick limit on cell division . </Td> </Tr> </Table> <Tr> <Th> Enzyme </Th> <Th> Function in DNA replication </Th> </Tr>

Where does dna synthesis begin on a chromosome