6E21

Joint X-ray/neutron structure of PKAc with products Sr2-ADP and phosphorylated peptide SP20

Summary for 6E21

• Entry DOI: 10.2210/pdb6e21/pdb
• Descriptor: cAMP-dependent protein kinase catalytic subunit alpha, pSP20, STRONTIUM ION, ... (5 entities in total)
• Functional Keywords: protein kinase, phosphorylated product complex, transferase
• Biological source: Mus musculus (Mouse); More
• Total number of polymer chains: 2
• Total formula weight: 44447.98

Authors

Kovalevsky, A.,Gerlits, O.O.,Taylor, S. (deposition date: 2018-07-10, release date: 2019-04-03, Last modification date: 2024-11-06)

Primary citation

Gerlits, O.,Weiss, K.L.,Blakeley, M.P.,Veglia, G.,Taylor, S.S.,Kovalevsky, A.
Zooming in on protons: Neutron structure of protein kinase A trapped in a product complex.
Sci Adv, 5:eaav0482-eaav0482, 2019

PubMed Abstract: The question vis-à-vis the chemistry of phosphoryl group transfer catalyzed by protein kinases remains a major challenge. The neutron diffraction structure of the catalytic subunit of cAMP-dependent protein kinase (PKA-C) provides a more complete chemical portrait of key proton interactions at the active site. By using a high-affinity protein kinase substrate (PKS) peptide, we captured the reaction products, dephosphorylated nucleotide [adenosine diphosphate (ADP)] and phosphorylated PKS (pPKS), bound at the active site. In the complex, the phosphoryl group of the peptide is protonated, whereas the carboxyl group of the catalytic Asp is not. Our structure, including conserved waters, shows how the peptide links the distal parts of the cleft together, creating a network that engages the entire molecule. By comparing slow-exchanging backbone amides to those determined by the NMR analysis of PKA-C with ADP and inhibitor peptide (PKI), we identified exchangeable amides that likely distinguish catalytic and inhibited states.

PubMed: 30906862
DOI: 10.1126/sciadv.aav0482

Experimental method

NEUTRON DIFFRACTION (2.5 Å)
X-RAY DIFFRACTION (2 Å)