Final answer:
The formation of a cointegrate structure in replicative transposition requires DNA replication machinery including DNA polymerases, primases, and helicases, as well as the complex interaction of over 20 enzymes and factors that make up the replisome.
Step-by-step explanation:
Fusion of two original molecules to form a cointegrate structure requires DNA replication machinery. The process is part of the replicative transposition mechanism and involves enzymes such as DNA polymerases, primases, and helicases to accurately initiate and propagate DNA synthesis. The replication fork, which is a Y-shaped structure, is crucial during the initiation of replication where a complex interaction of various enzymes takes place. These enzymes include DNA polymerase, which adds new nucleotides based on the original DNA strand's template, and RNA polymerase, which starts the process by synthesizing an RNA primer.
The semi-conservative DNA replication ensures that each of the two resulting DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand. During this process, multiple origins of replication forming multiple replicons ensure the complete duplication of the genome, which is necessary in the S phase of the cell cycle.
Importantly, the DNA replicase system, sometimes referred to as 'replisome', includes more than 20 enzymes and factors that work together to accurately and efficiently replicate DNA. This system is essential for the cointegrate formation in replicative transposition, enabling the transposon to be inserted into new locations within the genome.