Figure 3. Variability of the connections of CD_C2 to CT and CD_C1 in fungal ACC.

(a) Hinge properties of the CD_C2–CT connection analysed by a CT-based superposition of eight instances of the CD_C2-CT segment. For clarity, only one protomer of CthCD-CT_Cter1 is shown in full colour as reference. For other instances, CD_C2 domains are shown in transparent tube representation with only one helix each highlighted. The range of hinge bending is indicated and the connection points between CD_C2 and CT (blue) as well as between CD_C1 and CD_C2 (green and grey) are marked as spheres. (b) The interdomain interface of CD_C1 and CD_C2 exhibits only limited plasticity. Representation as in a, but the CD_C1 and CD_C2 are superposed based on CD_C2. One protomer of CthΔBCCP is shown in colour, the CD_L domains are omitted for clarity and the position of the phosphorylated serine based on SceCD is indicated with a red triangle. The connection points from CD_C1 to CD_C2 and to CD_L are represented by green spheres.