Crystal structure of C. parvum GNA1 in complex with acetyl-CoA and glucose 6P.

Experimental Data Snapshot

  • Resolution: 1.95 Å
  • R-Value Free: 0.313 
  • R-Value Work: 0.272 
  • R-Value Observed: 0.273 

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Plasmodium falciparum Apicomplexan-Specific Glucosamine-6-Phosphate N -Acetyltransferase Is Key for Amino Sugar Metabolism and Asexual Blood Stage Development.

Chi, J.Cova, M.de Las Rivas, M.Medina, A.Borges, R.J.Leivar, P.Planas, A.Uson, I.Hurtado-Guerrero, R.Izquierdo, L.

(2020) mBio 11

  • DOI: https://doi.org/10.1128/mBio.02045-20
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    UDP- N -acetylglucosamine (UDP-GlcNAc), the main product of the hexosamine biosynthetic pathway, is an important metabolite in protozoan parasites since its sugar moiety is incorporated into glycosylphosphatidylinositol (GPI) glycolipids and N - and O -linked glycans. Apicomplexan parasites have a hexosamine pathway comparable to other eukaryotic organisms, with the exception of the glucosamine-phosphate N -acetyltransferase (GNA1) enzymatic step that has an independent evolutionary origin and significant differences from nonapicomplexan GNA1s. By using conditional genetic engineering, we demonstrate the requirement of GNA1 for the generation of a pool of UDP-GlcNAc and for the development of intraerythrocytic asexual Plasmodium falciparum parasites. Furthermore, we present the 1.95 Å resolution structure of the GNA1 ortholog from Cryptosporidium parvum , an apicomplexan parasite which is a leading cause of diarrhea in developing countries, as a surrogate for P. falciparum GNA1. The in-depth analysis of the crystal shows the presence of specific residues relevant for GNA1 enzymatic activity that are further investigated by the creation of site-specific mutants. The experiments reveal distinct features in apicomplexan GNA1 enzymes that could be exploitable for the generation of selective inhibitors against these parasites, by targeting the hexosamine pathway. This work underscores the potential of apicomplexan GNA1 as a drug target against malaria. IMPORTANCE Apicomplexan parasites cause a major burden on global health and economy. The absence of treatments, the emergence of resistances against available therapies, and the parasite's ability to manipulate host cells and evade immune systems highlight the urgent need to characterize new drug targets to treat infections caused by these parasites. We demonstrate that glucosamine-6-phosphate N -acetyltransferase (GNA1), required for the biosynthesis of UDP- N -acetylglucosamine (UDP-GlcNAc), is essential for P. falciparum asexual blood stage development and that the disruption of the gene encoding this enzyme quickly causes the death of the parasite within a life cycle. The high-resolution crystal structure of the GNA1 ortholog from the apicomplexan parasite C. parvum , used here as a surrogate, highlights significant differences from human GNA1. These divergences can be exploited for the design of specific inhibitors against the malaria parasite.

  • Organizational Affiliation

    ISGlobal, HospitalClinic-Universitat de Barcelona, Barcelona, Spain.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Diamine acetyltransferase
A, B
152Cryptosporidium parvum Iowa IIMutation(s): 0 
Gene Names: SSATcgd4_4000
Find proteins for Q5CPU3 (Cryptosporidium parvum (strain Iowa II))
Explore Q5CPU3 
Go to UniProtKB:  Q5CPU3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ5CPU3
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.95 Å
  • R-Value Free: 0.313 
  • R-Value Work: 0.272 
  • R-Value Observed: 0.273 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.693α = 90
b = 70.089β = 90
c = 71.85γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2020-09-30
    Type: Initial release
  • Version 1.1: 2020-11-04
    Changes: Database references