3QAM

Crystal Structure of Glu208Ala mutant of catalytic subunit of cAMP-dependent protein kinase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.92 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

A conserved Glu-Arg salt bridge connects coevolved motifs that define the eukaryotic protein kinase fold.

Yang, J.Wu, J.Steichen, J.M.Kornev, A.P.Deal, M.S.Li, S.Sankaran, B.Woods, V.L.Taylor, S.S.

(2012) J.Mol.Biol. 415: 666-679

  • DOI: 10.1016/j.jmb.2011.11.035
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Eukaryotic protein kinases (EPKs) feature two coevolved structural segments, the Activation segment, which starts with the Asp-Phe-Gly (DFG) and ends with the Ala-Pro-Glu (APE) motifs, and the helical GHI subdomain that comprises αG-αH-αI helices. Eu ...

    Eukaryotic protein kinases (EPKs) feature two coevolved structural segments, the Activation segment, which starts with the Asp-Phe-Gly (DFG) and ends with the Ala-Pro-Glu (APE) motifs, and the helical GHI subdomain that comprises αG-αH-αI helices. Eukaryotic-like kinases have a much shorter Activation segment and lack the GHI subdomain. They thus lack the conserved salt bridge interaction between the APE Glu and an Arg from the GHI subdomain, a hallmark signature of EPKs. Although the conservation of this salt bridge in EPKs is well known and its implication in diseases has been illustrated by polymorphism analysis, its function has not been carefully studied. In this work, we use murine cAMP-dependent protein kinase (protein kinase A) as the model enzyme (Glu208 and Arg280) to examine the role of these two residues. We showed that Ala replacement of either residue caused a 40- to 120-fold decrease in catalytic efficiency of the enzyme due to an increase in K(m)(ATP) and a decrease in k(cat). Crystal structures, as well as solution studies, also demonstrate that this ion pair contributes to the hydrophobic network and stability of the enzyme. We show that mutation of either Glu or Arg to Ala renders both mutant proteins less effective substrates for upstream kinase phosphoinositide-dependent kinase 1. We propose that the Glu208-Arg280 pair serves as a center hub of connectivity between these two structurally conserved elements in EPKs. Mutations of either residue disrupt communication not only between the two segments but also within the rest of the molecule, leading to altered catalytic activity and enzyme regulation.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA 92093, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
cAMP-dependent protein kinase catalytic subunit alpha
E
350Mus musculusMutation(s): 1 
Gene Names: Prkaca (Pkaca)
EC: 2.7.11.11
Find proteins for P05132 (Mus musculus)
Go to UniProtKB:  P05132
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Protein kinase inhibitor
I
19Mus musculusMutation(s): 0 
Gene Names: Pkia
Find proteins for P63248 (Mus musculus)
Go to UniProtKB:  P63248
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ATP
Query on ATP

Download SDF File 
Download CCD File 
E
ADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O13 P3
ZKHQWZAMYRWXGA-KQYNXXCUSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
E
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP
E
L-PEPTIDE LINKINGC3 H8 N O6 PSER
TPO
Query on TPO
E
L-PEPTIDE LINKINGC4 H10 N O6 PTHR
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.92 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.195 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 48.412α = 90.00
b = 79.639β = 113.28
c = 60.800γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
HKL-2000data reduction
CNSrefinement
ADSCdata collection
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-12-07
    Type: Initial release
  • Version 1.1: 2013-06-19
    Type: Database references