Unveiling the structure, function and dynamics of StmPr1 in Stenotrophomonas maltophilia virulence

Max Sommer1, Amr Negm2,3, Lasse Outzen4

  • 1Department of Chemistry, Institute of Biochemistry and Molecular Biology, Laboratory for Structural Biology of Infection and Inflammation, University of Hamburg, c/o DESY, Build. 22a. Notkestr. 85, 22603, Hamburg, Germany. m.sommer.92@gmx.de.

Scientific Reports
|June 20, 2025
PubMed

Insights

Multi-resistant Stenotrophomonas maltophilia infections are a growing crisis. This study analyzes StmPr1, a key virulence factor, revealing its structure and potential as a drug target for new therapies.

Area of Science:

  • Microbiology
  • Structural Biology
  • Drug Discovery

Background:

  • Multi-resistant Gram-negative bacteria, particularly Stenotrophomonas maltophilia, represent a significant global health threat.
  • S. maltophilia is an opportunistic pathogen causing infections in hospital settings, often associated with medical devices and respiratory co-infections, as seen during the COVID-19 pandemic.
  • StmPr1, an excreted serine protease, is identified as the primary virulence factor of S. maltophilia.

Purpose of the Study:

  • To conduct a detailed structural and functional analysis of the S. maltophilia virulence factor, StmPr1.
  • To investigate the autoproteolytic activity of StmPr1 and its implications for enzyme function and stability.
  • To evaluate the potential of peptide-based inhibitors, specifically Bortezomib, as therapeutic agents against S. maltophilia infections.

Main Methods:

  • X-ray crystallography was employed to determine the structure of StmPr1 at high resolution (1.64–2.08 Å).
  • Molecular dynamic simulations and small-angle X-ray scattering (SAXS) experiments were utilized to analyze protein dynamics and structural characteristics.
  • Structure-function analyses were performed to understand the role of the C-terminal extension in StmPr1 folding and stability.

Main Results:

  • The study revealed a unique autoproteolytic mechanism in StmPr1, leading to a truncated active enzyme.
  • The C-terminal extension of StmPr1 was found to be crucial for its proper folding and stability.
  • Structural and functional data indicate that StmPr1 is a promising target for developing novel therapeutic strategies.

Conclusions:

  • Understanding the structural and functional intricacies of StmPr1 provides critical insights into S. maltophilia pathogenesis.
  • The identified autoproteolytic activity and the role of the C-terminal extension offer new avenues for targeting this virulence factor.
  • StmPr1 represents a viable target for drug discovery efforts aimed at combating S. maltophilia infections.

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