Fig. 2.6.
Crystal structure of E. coli Rep helicase (PDB code 1UAA [88]) in the open and closed conformations. Rep consists of four domains 1A, 1B, 2A, and 2B which are colored grey, red, green, and cyan, respectively. The open (a) and closed (b) conformations differ by rotations of around 130° of the 2B domain about a hinge region connecting it to the 2A domain [167]. The other domains are unchanged in both forms
