origin of replication

Introduction

origins of replication are typically assigned names containing ori

Function

• sequence in a genome at which replication is initiated
• binds origin of replication complex which, with help from two further protein factors (Cdc6 & Cdt1), load the minichromosome maintenance protein complex
• once assembled, pre-replication complex unwinds, & begins to copy DNA
• DNA replication may proceed from this point bidirectionally or unidirectionally
• eukaryotes often have multiple origins of replication on each linear chromosome, with up to 100,000 present in a single human cell
• many origins of replication shortens time of DNA replication
• the segment of DNA that is copied starting from each unique replication origin is called a replicon

Structure

• AT rich DNA
• DNA sequences at the replication origins vary
• despite this sequence variation, all the origins form a base for assembly of the origin of replication complex

More general terms

• biochemistry

Additional terms

• origin of replication complex (origin recognition complex, ORC)
• replicon