<P> DNA replication may proceed from this point bidirectionally or unidirectionally . </P> <P> The specific structure of the origin of replication varies somewhat from species to species, but all share some common characteristics such as high AT content (repeats of adenine and thymine are easier to separate because their base stacking interactions are not as strong as those of guanine and cytosine). The origin of replication binds the pre-replication complex, a protein complex that recognizes, unwinds, and begins to copy DNA . </P> <P> The origin of replication are classified in two ways: </P> <Ul> <Li> Narrow or broad host range </Li> <Li> High - or low - copy number . </Li> </Ul>

The origin of replication is a specific site in the genome at which dna replication is initiated