1JLU

Crystal Structure of the Catalytic Subunit of cAMP-dependent Protein Kinase Complexed with a Phosphorylated Substrate Peptide and Detergent

Summary for 1JLU

• Entry DOI: 10.2210/pdb1jlu/pdb
• Related: 1APM 1ATP
• Descriptor: AMP-DEPENDENT PROTEIN KINASE, ALPHA-CATALYTIC SUBUNIT, CAMP-DEPENDENT PROTEIN KINASE INHIBITOR, MUSCLE/BRAIN FORM, N-OCTANE, ... (4 entities in total)
• Functional Keywords: protein kinase-phosphorylated substrate complex, transferase-transferase inhibitor complex, transferase/transferase inhibitor
• Biological source: Mus musculus (house mouse); More
• Cellular location: Cytoplasm . Isoform 2: Cell projection, cilium, flagellum : P05132
• Total number of polymer chains: 2
• Total formula weight: 43050.91

Authors

Madhusudan,Trafny, E.A.,Xuong, N.-H.,Adams, J.A.,Ten Eyck, L.F.,Taylor, S.S.,Sowadski, J.M. (deposition date: 2001-07-16, release date: 2001-08-01, Last modification date: 2024-11-20)

Primary citation

Madhusudan,Trafny, E.A.,Xuong, N.H.,Adams, J.A.,Ten Eyck, L.F.,Taylor, S.S.,Sowadski, J.M.
cAMP-dependent protein kinase: crystallographic insights into substrate recognition and phosphotransfer.
Protein Sci., 3:176-187, 1994

PubMed Abstract: The crystal structure of ternary and binary substrate complexes of the catalytic subunit of cAMP-dependent protein kinase has been refined at 2.2 and 2.25 A resolution, respectively. The ternary complex contains ADP and a 20-residue substrate peptide, whereas the binary complex contains the phosphorylated substrate peptide. These 2 structures were refined to crystallographic R-factors of 17.5 and 18.1%, respectively. In the ternary complex, the hydroxyl oxygen OG of the serine at the P-site is 2.7 A from the OD1 atom of Asp 166. This is the first crystallographic evidence showing the direct interaction of this invariant carboxylate with a peptide substrate, and supports the predicted role of Asp 166 as a catalytic base and as an agent to position the serine -OH for nucleophilic attack. A comparison of the substrate and inhibitor ternary complexes places the hydroxyl oxygen of the serine 2.7 A from the gamma-phosphate of ATP and supports a direct in-line mechanism for phosphotransfer. In the binary complex, the phosphate on the Ser interacts directly with the epsilon N of Lys 168, another conserved residue. In the ternary complex containing ATP and the inhibitor peptide, Lys 168 interacts electrostatically with the gamma-phosphate of ATP (Zheng J, Knighton DR, Ten Eyck LF, Karlsson R, Xuong NH, Taylor SS, Sowadski JM, 1993, Biochemistry 32:2154-2161). Thus, Lys 168 remains closely associated with the phosphate in both complexes. A comparison of this binary complex structure with the recently solved structure of the ternary complex containing ATP and inhibitor peptide also reveals that the phosphate atom traverses a distance of about 1.5 A following nucleophilic attack by serine and transfer to the peptide. No major conformational changes of active site residues are seen when the substrate and product complexes are compared, although the binary complex with the phosphopeptide reveals localized changes in conformation in the region corresponding to the glycine-rich loop. The high B-factors for this loop support the conclusion that this structural motif is a highly mobile segment of the protein.

PubMed: 8003955

Experimental method

X-RAY DIFFRACTION (2.25 Å)