IspE kinase as an anti-infective target: Role of a hydrophobic pocket in inhibitor binding

Structure. 2024 Dec 5;32(12):2390-2398.e2. doi: 10.1016/j.str.2024.10.009. Epub 2024 Nov 6.

Abstract

Enzymes of the methylerythritol phosphate (MEP) pathway are potential targets for antimicrobial drug discovery. Here, we focus on 4-diphosphocytidyl-2-C-methyl-D-erythritol (IspE) kinase from the MEP pathway. We use biochemical and structural biology methods to investigate homologs from pathogenic microorganisms; Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii. We determined the X-ray crystal structures of IspE-inhibitor complexes and studied inhibitors' binding modes targeting the substrate pocket. The experimental results indicate the need for distinct inhibitor strategies due to structural differences among IspE homologs, particularly for A. baumannii IspE, which displays a unique inhibitory profile due to a tighter hydrophobic subpocket in the substrate binding site. This study enhances our understanding of the MEP enzymes and sets the stage for structure-based drug design of selective inhibitors to combat pathogenic microorganisms.

Keywords: IspE kinase; IspE kinase complex structures; IspE kinase substrate-competetive inhibitors; MEP pathway.

MeSH terms

  • Acinetobacter baumannii* / enzymology
  • Acinetobacter baumannii* / metabolism
  • Bacterial Proteins / antagonists & inhibitors
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Binding Sites
  • Catalytic Domain
  • Crystallography, X-Ray
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology
  • Escherichia coli Proteins / antagonists & inhibitors
  • Escherichia coli Proteins / chemistry
  • Escherichia coli Proteins / metabolism
  • Escherichia coli* / enzymology
  • Escherichia coli* / metabolism
  • Hydrophobic and Hydrophilic Interactions*
  • Klebsiella pneumoniae* / enzymology
  • Klebsiella pneumoniae* / metabolism
  • Models, Molecular
  • Phosphotransferases (Alcohol Group Acceptor) / antagonists & inhibitors
  • Phosphotransferases (Alcohol Group Acceptor) / chemistry
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism
  • Protein Binding

Substances

  • Escherichia coli Proteins
  • IspE protein, E coli
  • Phosphotransferases (Alcohol Group Acceptor)
  • Enzyme Inhibitors
  • Bacterial Proteins