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Excisionase in Pf filamentous prophage controls lysis-lysogeny decision-making in Pseudomonas aeruginosa

Yangmei Li1,2, Xiaoxiao Liu1, Kaihao Tang1

  • 1Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China.

Molecular Microbiology
|November 27, 2018
PubMed

Insights

Researchers identified key excisionase genes, XisF4 and XisF5, in Pf prophages. These proteins control Pseudomonas aeruginosa phage lysis-lysogeny switching and production, impacting biofilm development.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Bacteriology

Background:

  • Pf filamentous prophages are common in Pseudomonas aeruginosa.
  • These prophages influence biofilm formation.
  • The lysis-lysogeny switch control in Pf prophages is not well understood.

Purpose of the Study:

  • Identify and characterize excisionase genes in Pf4 and Pf5 prophages.
  • Investigate the role of these excisionases in prophage activity.
  • Elucidate the regulatory mechanisms governing Pf prophage lysogeny and production.

Main Methods:

  • Gene identification and characterization.
  • Prophage excision assays.
  • Gene expression analysis (e.g., transcription, promoter studies).
  • Protein-protein interaction studies (implied by repression).

Main Results:

  • XisF4 and XisF5 were identified as functional excisionases in Pf4 and Pf5, respectively.
  • Both promote prophage excision, but XisF5 is essential for Pf5.
  • XisF4 upregulates Pf4 replication initiator (PA0727).
  • XisF4 and Pf4r exhibit complex auto-regulation and cross-repression.
  • MvaT and MvaU repress Pf4 production by inhibiting xisF4.

Conclusions:

  • Pf prophage excisionases play crucial roles in regulating lysogeny and phage production.
  • A complex regulatory network involving excisionases, repressors, and host factors controls Pf prophage lifecycle.
  • Understanding these mechanisms is vital for managing Pseudomonas aeruginosa infections and biofilms.

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