Allosteric regulation of protein kinase a by nucleotides and metal ions

Protein Kinase A (PKA) is a macromolecular assembly composed of catalytic subunit (PKA-C) and regulatory (PKA-R) that harbors cyclic-nucleotide binding (CNB) domains. During its phosphorylation cycle, PKA-C experiences different conformational states depend on the nucleotides, metal ions substrates to active site. How changes in allosterically modulate interactions with CNB domains PKA-R currently unknown. Here we use optical tweezers selectively manipulate one domain (termed CNB-A) presence nucleotides.