Fig. 5.

Model of VcHfq properties. (a) Model explaining the lower stability of the VcHfq hexamer relative to EcHfq. VcHfq and EcHfq NTDs are shown as blue and magenta rings, respectively, with the intersubunit interface indicated by a sharp zigzag line for VcHfq and a curvy zigzag line for EcHfq. The CTRs are represented by triangles that do not interact with the intersubunit interface of the VcHfq NTD but do contribute to the intersubunit interface of the EcHfq NTD. (b) Model explaining the contribution of the CTR to VcHfq binding. The full-length VcHfq protein (top) utilizes multiple binding determinants (bright and dark red boxes) to bind at a specific site on the RNA (gray). VcHfq72, consisting of only the NTD, can only bind to a single binding determinant (bright red box) resulting in reduced binding specificity.