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Rv1818c-encoded PE_PGRS protein of Mycobacterium tuberculosis is surface exposed and influences bacterial cell

Giovanni Delogu1, Cinzia Pusceddu, Alessandra Bua

  • 1Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/b, 07100 Sassari, Italy. gdelogu@rm.unicatt.it

Molecular Microbiology
|April 23, 2004
PubMed

Insights

The PE_PGRS proteins of Mycobacterium tuberculosis are found in the cell wall, influencing bacterial shape and colony formation. Their regulated expression may impact mycobacterial survival and pathogenesis.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genomics

Background:

  • The PE multigene family of Mycobacterium tuberculosis was identified through genomic sequencing.
  • The biological functions of PE and PE_PGRS proteins remain largely unknown.
  • This study investigates a representative PE_PGRS gene, Rv1818c/PE_PGRS33.

Purpose of the Study:

  • To determine the subcellular localization of the PE_PGRS33 protein.
  • To elucidate the roles of the PE and PGRS domains in protein function.
  • To understand the implications of PE gene expression for mycobacterial survival.

Main Methods:

  • Cell fractionation studies were performed.
  • Fluorescence analysis using green fluorescent protein (GFP)-tagged proteins.
  • Overexpression of Rv1818c in Mycobacterium smegmatis and M. tuberculosis.

Main Results:

  • The Rv1818c gene product localizes to the mycobacterial cell wall, particularly at the cell poles.
  • The PE domain is essential for subcellular localization.
  • The PGRS domain influences bacterial shape and colony morphology upon overexpression.

Conclusions:

  • PE_PGRS and PE proteins are associated with the mycobacterial cell wall.
  • These proteins impact cellular structure and colony formation.
  • Regulated PE gene expression could be crucial for mycobacterial pathogenesis and survival.

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