Structure of Urocanate Hydratase from the protozoan Trypanosoma cruzi

Int J Biol Macromol. 2020 Mar 1:146:716-724. doi: 10.1016/j.ijbiomac.2019.12.101. Epub 2019 Dec 13.

Abstract

The enzyme Urocanate Hydratase (UH) participates in the catabolic pathway of L-histidine. Trypanosoma cruzi Urocanate Hydratase (TcUH) is identified as a therapeutic molecular target in the WHO/TDR Targets Database. We report the 3D structure determination and number of features of TcUH, and compared it to other few available bacterial UH structures. Each monomer presents two domains and one NAD+ molecule. Superpositions revealed differences in the relative orientation of domains within monomers, such that TcUH monomer A resembles Urocanate Hydratase from Geobacillus kaustophilus (GkUH) (open conformation), while monomer C resembles Urocanate Hydratase from Pseudomonas putida (PpUH) and Urocanate Hydratase from Bacillus subtilis (BsUH) (closed conformations). We use the structure of TcUH to make considerations about 3 non-deleterious and 2 deleterious mutations found in human UHs: non-deleterious mutations could be accommodated without large displacements or interaction interruptions, whereas deleterious mutations in one case might disrupt an α-helix (as previously suggested) and in the other case, besides disrupting the enzyme interaction with the substrate, might interfere with interdomain movement.

Keywords: Chagas disease; Histidine metabolism; Human Urocanate Hydratase deleterious mutations; Interdomain movement; Trypanosoma cruzi; Urocanate Hydratase.

MeSH terms

  • Amino Acid Sequence
  • Bacillus subtilis / enzymology
  • Cloning, Molecular
  • Crystallization
  • Geobacillus / enzymology
  • Histidine
  • NAD / ultrastructure
  • Protein Conformation, alpha-Helical
  • Pseudomonas putida / enzymology
  • Reproducibility of Results
  • Sequence Alignment
  • Trypanosoma cruzi / enzymology*
  • Urocanate Hydratase / ultrastructure*

Substances

  • NAD
  • Histidine
  • Urocanate Hydratase

Supplementary concepts

  • Geobacillus kaustophilus