1REJ

Crystal structure of cAMP-dependent protein kinase complexed with balanol analog 1

Summary for 1REJ

• Entry DOI: 10.2210/pdb1rej/pdb
• Related: 1ATP 1BX6 1RE8
• Descriptor: cAMP-dependent protein kinase, alpha-catalytic subunit, 3-[(4-HYDROXYBENZOYL)AMINO]AZEPAN-4-YL 4-HYDROXYBENZOATE (3 entities in total)
• Functional Keywords: protein kinase, natural product inhibitor, ligand binding, specificity determinants, conformational malleability, transferase
• Biological source: Mus musculus (house mouse)
• Cellular location: Cytoplasm . Isoform 2: Cell projection, cilium, flagellum : P05132
• Total number of polymer chains: 1
• Total formula weight: 41027.71

Authors

Akamine, P.,Madhusudan,Brunton, L.L.,Ou, H.D.,Canaves, J.M.,Xuong, N.H.,Taylor, S.S. (deposition date: 2003-11-06, release date: 2004-02-24, Last modification date: 2024-10-30)

Primary citation

Akamine, P.,Madhusudan,Brunton, L.L.,Ou, H.D.,Canaves, J.M.,Xuong, N.H.,Taylor, S.S.
Balanol analogues probe specificity determinants and the conformational malleability of the cyclic 3',5'-adenosine monophosphate-dependent protein kinase catalytic subunit
Biochemistry, 43:85-96, 2004

PubMed Abstract: The protein kinase family is a prime target for therapeutic agents, since unregulated protein kinase activities are linked to myriad diseases. Balanol, a fungal metabolite consisting of four rings, potently inhibits Ser/Thr protein kinases and can be modified to yield potent inhibitors that are selective-characteristics of a desirable pharmaceutical compound. Here, we characterize three balanol analogues that inhibit cyclic 3',5'-adenosine monophosphate-dependent protein kinase (PKA) more specifically and potently than calcium- and phospholipid-dependent protein kinase (PKC). Correlation of thermostability and inhibition potency suggests that better inhibitors confer enhanced protection against thermal denaturation. Crystal structures of the PKA catalytic (C) subunit complexed to each analogue show the Gly-rich loop stabilized in an "intermediate" conformation, disengaged from important phosphoryl transfer residues. An analogue that perturbs the PKA C-terminal tail has slightly weaker inhibition potency. The malleability of the PKA C subunit is illustrated by active site residues that adopt alternate rotamers depending on the ligand bound. On the basis of sequence homology to PKA, a preliminary model of the PKC active site is described. The balanol analogues serve to test the model and to highlight differences in the active site local environment of PKA and PKC. The PKA C subunit appears to tolerate balanol analogues with D-ring modifications; PKC does not. We attribute this difference in preference to the variable B helix and C-terminal tail. By understanding the details of ligand binding, more specific and potent inhibitors may be designed that differentiate among closely related AGC protein kinase family members.

PubMed: 14705934

Experimental method

X-RAY DIFFRACTION (2.2 Å)