Pre-replication complex

A pre-replication complex is a protein complex that forms at the origin of replication during the initiation step of DNA replication.

The following factors make up the complex:

• A helicase, which unwinds the DNA ahead of the fork (dnaA).
• A primase, which generates an RNA primer to be used in DNA replication (dnaG).
• A DNA holoenzyme, which is actually a complex of enzymes that performs the actual replication.