Replikacja u eukariontów

Most prokaryotic factors utilized during replication have equivalents that play similar roles in eukaryotic DNA duplication.

This process initiates at an origin of replication, to which a recognition complex binds. Helicase is then attracted to the site and separates the strands of DNA, generating a bubble with two forks.

Primase also arrives and generates RNA primers, which, as helicase moves, DNA polymerase elongates with new DNA. As in prokaryotes, the newly-formed leading strand grows continuously, following the replication fork.

Conversely, the lagging strand is manufactured in small Okazaki fragments, traveling opposite the fork.

Due to multiple factors, the DNA template used to generate the leading strand in 1/2 of this structure creates the lagging strand in the other.

Interestingly, various origins of replication exist on a linear eukaryotic chromosome, and replication terminates when their associated spheres coalesce. Primers are then eliminated via enzymes like RNAse and swapped for DNA. Afterwards, DNA ligase attaches any segments.

However, when the end primer disappears from the lagging strand, the space remains empty, and there is an uncopied stretch of DNA template abutting it. To combat this, an enzyme called telomerase affixes to the overhanging region and elongates it with a non-coding DNA sequence.

Primase and DNA polymerase act upon this extended region, creating a telomere cap that protects against loss of coding DNA from the lagging strand during multiple replications.

Thus eukaryotic DNA replication ends with two DNA molecules, each with a parental and newly-synthesized strand, numerous origins of replication, and telomeres.