. "Full activity of most CDKs is dependent on CAK mediated phosphorylation at a conserved residue (Thr 161 in Cdc2). This modification is thought to improve substrate binding. Cyclin B:Cdc2 complexes have considerably low activity in the absence of CAK mediated phosphorylation (Desai et al 1995)."^^ . . . . . . "CAK-mediated phosphorylation of Cyclin B1:Cdc2 complexes"^^ . . . . .