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Assembly Formation of P65 Protein, Featured by an Intrinsically Disordered Region Involved in Gliding Machinery of

Masaru Yabe1, Takuma Toyonaga1,2, Miki Kinoshita1,3,4

  • 1Department of Biology, Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.

Biomolecules
|March 28, 2025
PubMed

Insights

Mycoplasma pneumoniae uses P65 protein to stabilize its attachment organelle. This protein forms a multimer with a central globule and projections, crucial for bacterial gliding motility.

Area of Science:

  • Microbiology
  • Structural Biology
  • Biochemistry

Background:

  • Mycoplasma pneumoniae is a human pathogen known for its unique gliding motility mechanism.
  • The attachment organelle is a key structure for M. pneumoniae adherence and motility, comprising surface and core proteins.
  • P65 is a core component of the attachment organelle, essential for stabilizing other proteins.

Purpose of the Study:

  • To elucidate the structure and function of the P65 protein within the Mycoplasma pneumoniae attachment organelle.
  • To determine how P65 contributes to the stability and organization of the organelle.

Main Methods:

  • Bio-physical techniques including size exclusion chromatography, analytical centrifugation, circular dichroism spectroscopy, and small-angle X-ray scattering.
  • Limited proteolysis and negative staining electron microscopy were employed to analyze protein structure and interactions.
  • Amino acid sequence analysis predicted intrinsically disordered and coiled-coil regions within P65.

Main Results:

  • P65 forms a multimeric complex characterized by a central globule (30x23 nm) with multiple projections (14 nm length).
  • The C-terminal region of P65 is implicated in the multimerization process.
  • The intrinsically disordered N-terminal region of P65 is suggested to form a filamentary structure.

Conclusions:

  • P65 plays a critical role in the structural integrity of the M. pneumoniae attachment organelle.
  • The distinct structural features of P65, including its multimeric globule and filament-forming N-terminus, are essential for its function.
  • Understanding P65's structure provides insights into the mechanism of bacterial adhesion and motility.
Keywords:
adhesinadhesioncell motilityelectron microscopyprotein structuresmall-angle X-ray scattering

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