4DG0

Crystal structure of myristoylated WT catalytic subunit of cAMP-dependent protein kinase in complex with SP20 and AMP-PNP

Summary for 4DG0

• Entry DOI: 10.2210/pdb4dg0/pdb
• Related: 1ATP 1CTP 1JBP 4DFX 4DFZ 4DG2
• Descriptor: cAMP-dependent protein kinase catalytic subunit alpha, cAMP-dependent protein kinase inhibitor alpha, MYRISTIC ACID, ... (6 entities in total)
• Functional Keywords: protein kinase, myristoylated, phosphotransferase of ser/thr, mg, pki, pka regulatory subunits, phosphorylated on s139, t197, s338, myristoylated on g1, transferase-transferase inhibitor complex, transferase/transferase inhibitor
• Biological source: Mus musculus (mouse); More
• Cellular location: Cytoplasm: P05132
• Total number of polymer chains: 2
• Total formula weight: 43719.86

Authors

Bastidas, A.C.,Steichen, J.M.,Taylor, S.S. (deposition date: 2012-01-24, release date: 2012-06-06, Last modification date: 2024-11-27)

Primary citation

Bastidas, A.C.,Deal, M.S.,Steichen, J.M.,Keshwani, M.M.,Guo, Y.,Taylor, S.S.
Role of N-terminal myristylation in the structure and regulation of cAMP-dependent protein kinase.
J.Mol.Biol., 422:215-229, 2012

PubMed Abstract: The catalytic (C) subunit of cAMP-dependent protein kinase [protein kinase A (PKA)] is a major target of cAMP signaling, and its regulation is of fundamental importance to biological processes. One mode of regulation is N-myristylation, which has eluded structural and functional characterization so far because most crystal structures are of the non-myristylated enzyme, are phosphorylated on Ser10, and generally lack electron density for the first 13 residues. We crystallized myristylated wild-type (WT) PKA and a K7C mutant as binary (bound to a substrate peptide) and ternary [bound to a substrate peptide and adenosine-5'-(β,γ-imido)triphosphate] complexes. There was clear electron density for the entire N-terminus in the binary complexes, both refined to 2.0 Å, and K7C ternary complex, refined to 1.35 Å. The N-termini in these three structures display a novel conformation with a previously unseen helix from residues 1 to 7. The K7C mutant appears to have a more stable N-terminus, and this correlated with a significant decrease in the B-factors for the N-terminus in the myr-K7C complexes compared to the WT binary complex. The N-terminus of the myristylated WT ternary complex, refined to 2.0 Å, was disordered as in previous structures. In addition to a more ordered N-terminus, the myristylated K7C mutant exhibited a 53% increase in k(cat). The effect of nucleotide binding on the structure of the N-terminus in the WT protein and the kinetic changes in the K7C protein suggest that myristylation or occupancy of the myristyl binding pocket may serve as a site for allosteric regulation in the C-subunit.

PubMed: 22617327
DOI: 10.1016/j.jmb.2012.05.021

Experimental method

X-RAY DIFFRACTION (2 Å)