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Pseudomonas aeruginosa Type III Secretory Toxin ExoU and Its Predicted Homologs

Teiji Sawa1, Saeko Hamaoka2, Mao Kinoshita3

  • 1Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan. anesth@koto.kpu-m.ac.jp.

Toxins
|October 30, 2016
PubMed

Insights

Pseudomonas aeruginosa ExoU toxin homologs were found in 17 Pseudomonas species and 8 other Gram-negative bacteria. Comparative analysis revealed conserved and nonconserved regions, aiding understanding of ExoU toxin characteristics.

Area of Science:

  • Microbiology
  • Genomics
  • Bacterial Pathogenesis

Background:

  • Pseudomonas aeruginosa ExoU is a type III secretory toxin and a key virulence factor.
  • ExoU possesses patatin-like phospholipase activity, contributing to acute lung injury and sepsis.
  • Its role in severe infections, particularly in immunocompromised individuals, highlights its clinical significance.

Purpose of the Study:

  • To identify protein sequences homologous to Pseudomonas aeruginosa ExoU in a broader range of bacterial species.
  • To analyze the conservation and variation within these homologous sequences.
  • To provide a foundation for further comparative studies on the ExoU toxin.

Main Methods:

  • Utilized an updated bacterial genome database to search for ExoU homologs.
  • Performed phylogenetic analyses based on predicted primary amino acid sequences.
  • Conducted sequence alignment to identify conserved and nonconserved regions.

Main Results:

  • Identified ExoU homologs in 17 additional Pseudomonas species.
  • Discovered homologous sequences in 8 Gram-negative bacteria from genera Photorhabdus, Aeromonas, and Paludibacterium.
  • Alignment revealed both highly conserved and variable regions within the identified sequences.

Conclusions:

  • The study expands the known distribution of ExoU-like toxins beyond Pseudomonas aeruginosa.
  • Comparative analysis of these homologs offers insights into the structural and functional diversity of the toxin.
  • Further research on these homologs can elucidate the specific characteristics of Pseudomonas aeruginosa ExoU.
Keywords:
ExoUPseudomonas aeruginosapatatinphospholipase A2type III secretion system

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