Prepriming complex

A group of proteins form the prepriming complex. They recognize the origin of replication (dnaA protein), maintain the separation of the parental strands (single-stranded DNA-binding proteins), and unwind the double helix ahead of the advancing replication fork (helicase). 

The polymerase holoenzyme assembles. The DNA polymerase ITT holoen-zyme assembles on the prepriming complex, initiated by interactions between DnaB and the sliding clamp subunit of DNA polymerase 111. These interactions also trigger ATP hydrolysis within the DnaA subunits, signaling the initiation of DNA replication. The breakup of the DnaA assembly prevents additional rounds of replication from beginning at the replication origin. 

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