Abstract
Intrinsically disordered proteins/regions (IDPs/IDRs) frequently engage in dynamic charge:charge interactions, commonly referred to as 'fuzzy' interactions. These fuzzy interactions play critical roles in enzymatic regulation and substrate recruitment, especially for protein kinases and protein phosphatases. Here, we review recent advances that demonstrate how inter- and intramolecular fuzzy interactions among kinases and phosphatases and their cognate regulators and substrates allow for enzyme assembly, activation and substrate recruitment. We also highlight a unique mechanism of protein inhibition, where a protein phosphatase is inhibited by dynamic fuzzy interactions with its active site metals.