Iteron

Iterons are directly repeated DNA sequences which play an important role in regulation of plasmid copy number in bacterial cells.

Iterons complex with cognate replication (Rep) initiator proteins to achieve the required regulatory effect.

An iteron-containing plasmid origin of replication can be found containing about five iterons about 20 base pairs in length total.

These iterons provide a saturation site for initiator receptor proteins and promote replication, thus increasing plasmid copy number in a given cell.

[1][2] Another less prevalent limitation thought to be present in these iterons is the presence of extra repeats.

This operator contains half of the iteron sequence, making it able to bind the dimer and promote gene expression.

Four main limiting factors leading to no initiation of replication in iterons
Representation of the molecular structure of protein RepA, a known rep protein used in iterons