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RifP; a membrane protein involved in rifamycin export in Amycolatopsis mediterranei

Angel E Absalón1, Francisco J Fernández, Perla X Olivares

  • 1Depto. de Biotecnología, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana, Iztapalapa. AP 55-535, México, D.F., México.

Biotechnology Letters
|March 14, 2007
PubMed

Insights

The rifP gene in Amycolatopsis mediterranei exports rifamycin, preventing intracellular accumulation. Silencing this gene significantly reduced extracellular antibiotic production.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • The rifamycin gene cluster in Amycolatopsis mediterranei is crucial for antibiotic production.
  • The specific function of the rifP gene within this cluster remained uncharacterized.

Purpose of the Study:

  • To elucidate the role of the rifP gene in rifamycin biosynthesis and export.
  • To investigate the impact of rifP gene silencing on antibiotic production.

Main Methods:

  • Construction of an antisense cassette targeting the rifP gene.
  • Partial silencing of rifP using a plasmid-based system in Amycolatopsis mediterranei.
  • Analysis of extracellular rifamycin B levels and membrane protein fractions.

Main Results:

  • Partial silencing of the rifP gene led to a 70% reduction in extracellular rifamycin B.
  • A 53 kDa protein, corresponding to the rifP gene product, was absent in the membrane fraction of silenced strains.
  • Structural analysis suggested the rifP protein belongs to the Drug:H+ antiporter family.

Conclusions:

  • The rifP gene encodes a protein responsible for exporting rifamycin from Amycolatopsis mediterranei cells.
  • This export mechanism prevents intracellular antibiotic accumulation and is vital for efficient extracellular production.
  • The identified protein functions as a membrane transporter, likely a Drug:H+ antiporter.

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