text: The replication initiator protein (Rep) plays a key role in initiation of replication in plasmids. In its monomer form, Rep binds an iteron and promotes replication. The protein itself is known to contain two independent N-terminal and C-terminal globular domains that subsequently bind to two domains of the iteron. The dimer version of the protein is generally inactive in iteron binding, however it is known to bind to the repE operator. This operator contains half of the iteron sequence making it able to bind the dimer and promote gene expression.
  Plasmids containing iterons are all organized very similarly in structure.   The gene for Rep proteins is usually found directly downstream of the origin of replication. This means that the iterons themselves are known to regulate the synthesis of the rep proteins.