Crystal structure of glucokinase (NfHK) from Naegleria fowleri

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.187 
  • R-Value Work: 0.154 
  • R-Value Observed: 0.156 

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Enzymatic and Structural Characterization of theNaegleria fowleriGlucokinase.

Milanes, J.E.Suryadi, J.Abendroth, J.Van Voorhis, W.C.Barrett, K.F.Dranow, D.M.Phan, I.Q.Patrick, S.L.Rozema, S.D.Khalifa, M.M.Golden, J.E.Morris, J.C.

(2019) Antimicrob Agents Chemother 63

  • DOI: https://doi.org/10.1128/AAC.02410-18
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Infection with the free-living amoeba Naegleria fowleri leads to life-threatening primary amoebic meningoencephalitis. Efficacious treatment options for these infections are limited, and the mortality rate is very high (∼98%). Parasite metabolism may provide suitable targets for therapeutic design. Like most other organisms, glucose metabolism is critical for parasite viability, being required for growth in culture. The first enzyme required for glucose metabolism is typically a hexokinase (HK), which transfers a phosphate from ATP to glucose. The products of this enzyme are required for both glycolysis and the pentose phosphate pathway. However, the N. fowleri genome lacks an obvious HK homolog and instead harbors a glucokinase (Glck). The N. fowleri Glck (NfGlck) shares limited (25%) amino acid identity with the mammalian host enzyme ( Homo sapiens Glck), suggesting that parasite-specific inhibitors with anti-amoeba activity can be generated. Following heterologous expression, NfGlck was found to have a limited hexose substrate range, with the greatest activity observed with glucose. The enzyme had apparent K m values of 42.5 ± 7.3 μM and 141.6 ± 9.9 μM for glucose and ATP, respectively. The NfGlck structure was determined and refined to 2.2-Å resolution, revealing that the enzyme shares greatest structural similarity with the Trypanosoma cruzi Glck. These similarities include binding modes and binding environments for substrates. To identify inhibitors of NfGlck, we screened a small collection of inhibitors of glucose-phosphorylating enzymes and identified several small molecules with 50% inhibitory concentration values of <1 μM that may prove useful as hit chemotypes for further leads and therapeutic development against N. fowleri .

  • Organizational Affiliation

    Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Glucokinase449Naegleria fowleriMutation(s): 0 
Find proteins for A0A384E136 (Naegleria fowleri)
Explore A0A384E136 
Go to UniProtKB:  A0A384E136
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A384E136
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
ANP (Subject of Investigation/LOI)
Query on ANP

Download Ideal Coordinates CCD File 
C10 H17 N6 O12 P3
BGC (Subject of Investigation/LOI)
Query on BGC

Download Ideal Coordinates CCD File 
B [auth A]beta-D-glucopyranose
C6 H12 O6
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 202.48α = 90
b = 202.48β = 90
c = 68.79γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling
PDB_EXTRACTdata extraction
ARP/wARPmodel building
BUCCANEERmodel building
Cootmodel building

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2018-05-09
    Type: Initial release
  • Version 1.1: 2019-12-18
    Changes: Data collection, Database references
  • Version 1.2: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary
  • Version 1.3: 2023-10-04
    Changes: Data collection, Database references, Refinement description, Structure summary