PDBsum entry 1rek

Transferase

PDB id: 1rek

Contents

Protein chain

338 a.a. *

Ligands

B8L

PTL

Waters ×99

* Residue conservation analysis

PDB id:

1rek

Name:

Transferase

Title:

Crystal structure of camp-dependent protein kinase complexed with balanol analog 8

Structure:

Camp-dependent protein kinase, alpha-catalytic subunit. Chain: a. Synonym: pka c-alpha. Engineered: yes

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Gene: prkaca, pkaca. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

Resolution:

2.30Å R-factor: 0.218 R-free: 0.295

Authors:

P.Akamine,Madhusudan,L.L.Brunton,H.D.Ou,J.M.Canaves,N.H.Xuong, S.S.Taylor

Key ref:

P.Akamine et al. (2004). 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. PubMed id: 14705934

Date:

06-Nov-03 Release date: 24-Feb-04

Protein chain

P05132  (KAPCA_MOUSE) -  cAMP-dependent protein kinase catalytic subunit alpha from Mus musculus

Seq: 351 a.a.

Struc: 338 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.2.7.11.11 - cAMP-dependent protein kinase.
• Reaction:
  1. L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP + H⁺
  2. L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] + ADP + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

Biochemistry 43:85-96 (2004)

PubMed id: 14705934

Balanol analogues probe specificity determinants and the conformational malleability of the cyclic 3',5'-adenosine monophosphate-dependent protein kinase catalytic subunit.

P.Akamine, Madhusudan, L.L.Brunton, H.D.Ou, J.M.Canaves, N.H.Xuong, S.S.Taylor.

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.