For a cell to divide, it must first replicate its DNA. This process is initiated at particular points in the DNA, known as "origins '', which are targeted by initiator proteins. In E. coli this protein is DnaA; in yeast, this is the origin recognition complex. Sequences used by initiator proteins tend to be "AT - rich '' (rich in adenine and thymine bases), because A-T base pairs have two hydrogen bonds (rather than the three formed in a C-G pair) and thus are easier to strand - separate. Once the origin has been located, these initiators recruit other proteins and form the pre-replication complex, which unwinds the double - stranded DNA.
where does the process of replication occur in the cell
origins