Figure 3.

The region of the E. coli chromosome carrying oriC, the origin of replication, and neighboring genes. A recent review presents a detailed walkthrough of the various binding sites in oriC and the interactions with the DnaA protein and other factors in forming the orisome that is required to initiate replication (Leonard and Grimwade, 2015). DnaA boxes with high (dark blue boxes) and low (light blue boxes) affinity, respectively; positions of GATC sites (^*). However, in an exponentially growing culture containing cells of all ages only the R1, R2, and R4 are bound by DnaA protein (Samitt et al., 1989).