4IB1

Structure of cAMP dependent protein kinase A in complex with high K+ concentration, ADP and phosphorylated peptide pSP20

Summary for 4IB1

• Entry DOI: 10.2210/pdb4ib1/pdb
• Related: 4IAC 4IAD 4IAF 4IAI 4IAK 4IAY 4IAZ 4IB0 4IB3
• Descriptor: cAMP-dependent protein kinase catalytic subunit alpha, phosphorylated pseudo-substrate peptide pSP20, POTASSIUM ION, ... (5 entities in total)
• Functional Keywords: kinase enzyme, phosphotransfer, phosphorylated, transferase-peptide complex, transferase/peptide
• Biological source: Mus musculus (mouse); More
• Cellular location: Cytoplasm. Isoform 2: Cell projection, cilium, flagellum (By similarity): P05132
• Total number of polymer chains: 2
• Total formula weight: 44350.93

Authors

Gerlits, O.,Kovalevsky, A. (deposition date: 2012-12-07, release date: 2013-12-11, Last modification date: 2014-05-28)

Primary citation

Gerlits, O.,Das, A.,Keshwani, M.M.,Taylor, S.,Waltman, M.J.,Langan, P.,Heller, W.T.,Kovalevsky, A.
Metal-Free cAMP-Dependent Protein Kinase Can Catalyze Phosphoryl Transfer.
Biochemistry, 53:3179-3186, 2014

PubMed Abstract: X-ray structures of several ternary product complexes of the catalytic subunit of cAMP-dependent protein kinase (PKAc) have been determined with no bound metal ions and with Na(+) or K(+) coordinated at two metal-binding sites. The metal-free PKAc and the enzyme with alkali metals were able to facilitate the phosphoryl transfer reaction. In all studied complexes, the ATP and the substrate peptide (SP20) were modified into the products ADP and the phosphorylated peptide. The products of the phosphotransfer reaction were also found when ATP-γS, a nonhydrolyzable ATP analogue, reacted with SP20 in the PKAc active site containing no metals. Single turnover enzyme kinetics measurements utilizing (32)P-labeled ATP confirmed the phosphotransferase activity of the enzyme in the absence of metal ions and in the presence of alkali metals. In addition, the structure of the apo-PKAc binary complex with SP20 suggests that the sequence of binding events may become ordered in a metal-free environment, with SP20 binding first to prime the enzyme for subsequent ATP binding. Comparison of these structures reveals conformational and hydrogen bonding changes that might be important for the mechanism of catalysis.

PubMed: 24786636
DOI: 10.1021/bi5000965

Experimental method

X-RAY DIFFRACTION (1.63 Å)