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Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins
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Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins

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Synthesis of a bacteriophage MB78 late protein by novel ribosomal frameshifting

V Kolla1, M Chakravorty, B Pandey

  • 1Molecular Biology Unit, Institute of Medical Sciences, Banaras Hindu University, 221005, Varanasi, India. venkatadri.kolla@mail.tju.edu

Gene
|September 7, 2000
PubMed

Insights

Researchers found evidence of ribosomal frameshifting in bacteriophage MB78, a Salmonella typhimurium virus. This process explains how one gene in this virus produces two distinct proteins, impacting gene expression regulation.

Area of Science:

  • Molecular Biology
  • Virology
  • Genetics

Background:

  • Bacteriophage MB78, a virulent phage of Salmonella typhimurium, presents unique features for studying gene expression regulation.
  • A physical map of the phage genome has been established, facilitating molecular-level investigations.

Purpose of the Study:

  • To investigate the expression of late proteins in bacteriophage MB78.
  • To determine the mechanism responsible for the production of two distinct proteins from a single gene.

Main Methods:

  • In vitro transcription-translation assays were performed.
  • In vivo expression studies utilized pET expression vectors.
  • Mutagenesis of a putative slippery sequence (TTTAAAG) was conducted.

Main Results:

  • In vitro studies yielded a single 28kDa protein, while in vivo expression produced both 28kDa and 26kDa proteins.
  • A slippery sequence and a pseudoknot structure, key elements for ribosomal frameshifting, were identified.
  • Mutations in the slippery sequence eliminated the 26kDa protein, confirming the role of frameshifting.

Conclusions:

  • This study provides the first evidence of ribosomal frameshifting in bacteriophage MB78.
  • Ribosomal frameshifting explains the expression of two proteins from a single gene in this Salmonella typhimurium phage.
  • The findings contribute to understanding gene expression regulation in bacteriophages.

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