Figure 1. Three-dimensional fold and conformational states of PKA-C.
A) Ribbon diagram of the catalytic subunit of protein kinase A (PDB: 1ATP) shown with the C-spine scaffold (yellow surface), sandwiching the adenine moiety of ATP, and the peptide fragment of the heat stable protein kinase inhibitor (PKI5-24). B) Overlay of the glycine-rich loop of the open (PDB: 1J3H), intermediate (PDB:1BKX) and closed (PDB:1ATP) forms of PKA-C. (C). Electrostatic and hydrophobic contacts with ATP deduced from the 1ATP structure of PKA-C. (D) Chemical structures of the nucleotide analogues used in this study.