Structural evidence for product stabilization by the ribosomal mRNA helicase

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Hossein Amiri1, Harry F Noller2

  • 1Center for Molecular Biology of RNA and Department of Molecular, Cell and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California 95064, USA.

RNA (New York, N.Y.)
|December 16, 2018
PubMed

Insights

The ribosome unwinds messenger RNA (mRNA) structures during protein synthesis. A crystal structure reveals ribosomal protein uS3 may stabilize single-stranded mRNA, aiding this unwinding process.

Area of Science:

  • Molecular Biology
  • Structural Biology
  • Biochemistry

Background:

  • Protein synthesis involves ribosome translocation along messenger RNA (mRNA).
  • Ribosomes possess helicase activity to unwind mRNA structures encountered during translocation.
  • The precise mechanism of mRNA unwinding and the role of ribosomal proteins uS3, uS4, and uS5 are not fully understood.

Purpose of the Study:

  • To elucidate the mechanism of mRNA unwinding by the ribosome.
  • To investigate the potential role of ribosomal protein uS3 in the ribosome's helicase activity.

Main Methods:

  • X-ray crystallography of the *Escherichia coli* ribosome.

Main Results:

  • A crystal structure revealed single-stranded mRNA extending beyond the ribosome's mRNA tunnel entrance.
  • This mRNA interacted with a positively charged region on ribosomal protein uS3.
  • The binding appeared specific for single-stranded mRNA immediately preceding the tunnel entrance.

Conclusions:

  • Ribosomal protein uS3 may contribute to mRNA unwinding through product stabilization.
  • This interaction suggests a mechanism for how the ribosome helicase unwinds structured mRNA.
Keywords:
helicasemRNAribosomestructureuS3

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