Crystal structure of apo carboxy cGMP binding domain of Plasmodium falciparum PKG

Experimental Data Snapshot

  • Resolution: 1.89 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.177 
  • R-Value Observed: 0.180 

wwPDB Validation   3D Report Full Report

This is version 1.1 of the entry. See complete history


Crystal Structures of the Carboxyl cGMP Binding Domain of the Plasmodium falciparum cGMP-dependent Protein Kinase Reveal a Novel Capping Triad Crucial for Merozoite Egress.

Kim, J.J.Flueck, C.Franz, E.Sanabria-Figueroa, E.Thompson, E.Lorenz, R.Bertinetti, D.Baker, D.A.Herberg, F.W.Kim, C.

(2015) PLoS Pathog 11: e1004639-e1004639

  • DOI: https://doi.org/10.1371/journal.ppat.1004639
  • Primary Citation of Related Structures:  
    4OFF, 4OFG

  • PubMed Abstract: 

    The Plasmodium falciparum cGMP-dependent protein kinase (PfPKG) is a key regulator across the malaria parasite life cycle. Little is known about PfPKG's activation mechanism. Here we report that the carboxyl cyclic nucleotide binding domain functions as a "gatekeeper" for activation by providing the highest cGMP affinity and selectivity. To understand the mechanism, we have solved its crystal structures with and without cGMP at 2.0 and 1.9 Å, respectively. These structures revealed a PfPKG-specific capping triad that forms upon cGMP binding, and disrupting the triad reduces kinase activity by 90%. Furthermore, mutating these residues in the parasite prevents blood stage merozoite egress, confirming the essential nature of the triad in the parasite. We propose a mechanism of activation where cGMP binding allosterically triggers the conformational change at the αC-helix, which bridges the regulatory and catalytic domains, causing the capping triad to form and stabilize the active conformation.

  • Organizational Affiliation

    Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CGMP-dependent protein kinase144Plasmodium falciparumMutation(s): 0 
Find proteins for Q8I719 (Plasmodium falciparum (isolate 3D7))
Explore Q8I719 
Go to UniProtKB:  Q8I719
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8I719
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.89 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.177 
  • R-Value Observed: 0.180 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 25.781α = 90
b = 57.683β = 90
c = 82.78γ = 90
Software Package:
Software NamePurpose
Specdata collection
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-01-21
    Type: Initial release
  • Version 1.1: 2015-02-11
    Changes: Database references