3X2V

Michaelis-like complex of cAMP-dependent Protein Kinase Catalytic Subunit

Summary for 3X2V

• Entry DOI: 10.2210/pdb3x2v/pdb
• Related: 3X2U 3X2W
• Descriptor: cAMP-dependent protein kinase catalytic subunit alpha, Substrate Peptide, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: michaelis-like complex, protein-substrate, pkac-atpmg2 ternary, ser/thr kinase, atp binding, phosphorylation, transferase-peptide complex, transferase/peptide
• Biological source: Mus musculus (mouse); More
• Cellular location: Cytoplasm . Isoform 2: Cell projection, cilium, flagellum : P05132
• Total number of polymer chains: 2
• Total formula weight: 44512.55

Authors

Das, A.,Langan, P.,Gerlits, O.,Kovalevsky, A.Y.,Heller, W.T. (deposition date: 2015-01-02, release date: 2015-12-16, Last modification date: 2024-10-09)

Primary citation

Das, A.,Gerlits, O.,Parks, J.M.,Langan, P.,Kovalevsky, A.,Heller, W.T.
Protein Kinase A Catalytic Subunit Primed for Action: Time-Lapse Crystallography of Michaelis Complex Formation.
Structure, 23:2331-2340, 2015

PubMed Abstract: The catalytic subunit of the cyclic AMP-dependent protein kinase A (PKAc) catalyzes the transfer of the γ-phosphate of bound Mg2ATP to a serine or threonine residue of a protein substrate. Here, time-lapse X-ray crystallography was used to capture a series of complexes of PKAc with an oligopeptide substrate and unreacted Mg2ATP, including the Michaelis complex, that reveal important geometric rearrangements in and near the active site preceding the phosphoryl transfer reaction. Contrary to the prevailing view, Mg(2+) binds first to the M1 site as a complex with ATP and is followed by Mg(2+) binding to the M2 site. Concurrently, the target serine hydroxyl of the peptide substrate rotates away from the active site toward the bulk solvent, which breaks the hydrogen bond with D166. Lastly, the serine hydroxyl of the substrate rotates back toward D166 to form the Michaelis complex with the active site primed for phosphoryl transfer.

PubMed: 26585512
DOI: 10.1016/j.str.2015.10.005

Experimental method

X-RAY DIFFRACTION (1.77 Å)