Fig. 7: Insights into PhK activation.

a Cryo-EM structure of PhK in the presence of Ca²⁺. The density map of the D5_α–AID region is shown on the right. b A model of Ca²⁺-triggered de-inhibition and activation of PhK. Ca²⁺-free calmodulin binds to the γ-subunit in a compact conformation. Upon sensing Ca²⁺, calmodulin undergoes a conformational change and facilitates detachment and de-inhibition of KD. c A TEV protease cleavage site was introduced into the γ-subunit between αJ and AID. After TEV cleavage, KD was not pulled down by the α-subunit in the presence of Ca²⁺. This experiment has been repeated at least three times. d Overall structure of the ADP-bound β-subunit. The cryo-EM density map of the ADP-binding pocket is shown on the right. e Structural overlay of the apo (from the inactive PhK structure) and ADP-bound β-subunits.