The Structure of Phosphorylase Kinase Holoenzyme at 9.9 A ̊ Resolution and Location of the Catalytic Subunit and the Substrate Glycogen Phosphorylase

International audiencePhosphorylase kinase (PhK) coordinates hormonal and neuronal signals to initiate the breakdown of glycogen. The enzyme catalyses the phosphorylation of inactive glycogen phosphorylase b ( GPb) resulting in the formation of active glycogen phosphorylase a