Figure 8.

Model of DnaB loading via interaction between DnaB Leu¹⁶⁰ and DnaA Phe⁴⁶. A model of the structure of the open complex is shown as in Fig. 1. In addition, DnaB (NTD (dark green) and LH-CTD (pale green)), DnaC (cyan), DnaB Leu¹⁶⁰ site (purple), and DnaA Phe⁴⁶ site (dark red) are shown. Two or three protomers of the DnaB hexamer bind to domain I in DnaA pentamers on oriC, which recruits two DnaB hexamers and tethers them in a particular orientation. This conformation underlies the functional interaction of DnaB–DnaC complexes with the DnaA domain III site containing His¹³⁶ and the unwound region of oriC, promoting DnaB loading onto the oriC region.