3IDC

Crystal structure of (102-265)RIIb:C holoenzyme of cAMP-dependent protein kinase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.319 
  • R-Value Work: 0.241 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Novel isoform-specific interfaces revealed by PKA RIIbeta holoenzyme structures.

Brown, S.H.Wu, J.Kim, C.Alberto, K.Taylor, S.S.

(2009) J.Mol.Biol. 393: 1070-1082

  • DOI: 10.1016/j.jmb.2009.09.014
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The cAMP-dependent protein kinase catalytic (C) subunit is inhibited by two classes of functionally nonredundant regulatory (R) subunits, RI and RII. Unlike RI subunits, RII subunits are both substrates and inhibitors. Because RIIbeta knockout mice h ...

    The cAMP-dependent protein kinase catalytic (C) subunit is inhibited by two classes of functionally nonredundant regulatory (R) subunits, RI and RII. Unlike RI subunits, RII subunits are both substrates and inhibitors. Because RIIbeta knockout mice have important disease phenotypes, the RIIbeta holoenzyme is a target for developing isoform-specific agonists and/or antagonists. We also know little about the linker region that connects the inhibitor site to the N-terminal dimerization domain, although this linker determines the unique globular architecture of the RIIbeta holoenzyme. To understand how RIIbeta functions as both an inhibitor and a substrate and to elucidate the structural role of the linker, we engineered different RIIbeta constructs. In the absence of nucleotide, RIIbeta(108-268), which contains a single cyclic nucleotide binding domain, bound C subunit poorly, whereas with AMP-PNP, a non-hydrolyzable ATP analog, the affinity was 11 nM. The RIIbeta(108-268) holoenzyme structure (1.62 A) with AMP-PNP/Mn(2+) showed that we trapped the RIIbeta subunit in an enzyme:substrate complex with the C subunit in a closed conformation. The enhanced affinity afforded by AMP-PNP/Mn(2+) may be a useful strategy for increasing affinity and trapping other protein substrates with their cognate protein kinase. Because mutagenesis predicted that the region N-terminal to the inhibitor site might dock differently to RI and RII, we also engineered RIIbeta(102-265), which contained six additional linker residues. The additional linker residues in RIIbeta(102-265) increased the affinity to 1.6 nM, suggesting that docking to this surface may also enhance catalytic efficiency. In the corresponding holoenzyme structure, this linker docks as an extended strand onto the surface of the large lobe. This hydrophobic pocket, formed by the alphaF-alphaG loop and conserved in many protein kinases, also provides a docking site for the amphipathic helix of PKI. This novel orientation of the linker peptide provides the first clues as to how this region contributes to the unique organization of the RIIbeta holoenzyme.


    Organizational Affiliation

    Departments of Chemistry/Biochemistry and Pharmacology, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA 92093-0654, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
cAMP-dependent protein kinase catalytic subunit alpha
A
350Mus musculusMutation(s): 0 
Gene Names: Prkaca (Pkaca)
EC: 2.7.11.11
Find proteins for P05132 (Mus musculus)
Go to UniProtKB:  P05132
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
cAMP-dependent protein kinase type II-beta regulatory subunit
B
164Rattus norvegicusMutation(s): 0 
Gene Names: Prkar2b
Find proteins for P12369 (Rattus norvegicus)
Go to UniProtKB:  P12369
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MN
Query on MN

Download SDF File 
Download CCD File 
A
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
ANP
Query on ANP

Download SDF File 
Download CCD File 
A
PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER
C10 H17 N6 O12 P3
PVKSNHVPLWYQGJ-KQYNXXCUSA-N
 Ligand Interaction
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP
A
L-PEPTIDE LINKINGC3 H8 N O6 PSER
TPO
Query on TPO
A
L-PEPTIDE LINKINGC4 H10 N O6 PTHR
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.319 
  • R-Value Work: 0.241 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 179.272α = 90.00
b = 67.434β = 99.51
c = 47.325γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
HKL-2000data reduction
ADSCdata collection
REFMACrefinement
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-09-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance