Assembly and functionality of the ribosome with tethered subunits

Nat Commun. 2019 Feb 25;10(1):930. doi: 10.1038/s41467-019-08892-w.

Abstract

Ribo-T is an engineered ribosome whose small and large subunits are tethered together by linking 16S rRNA and 23S rRNA in a single molecule. Although Ribo-T can support cell proliferation in the absence of wild type ribosomes, Ribo-T cells grow slower than those with wild type ribosomes. Here, we show that cell growth defect is likely explained primarily by slow Ribo-T assembly rather than its imperfect functionality. Ribo-T maturation is stalled at a late assembly stage. Several post-transcriptional rRNA modifications and some ribosomal proteins are underrepresented in the accumulated assembly intermediates and rRNA ends are incompletely trimmed. Ribosome profiling of Ribo-T cells shows no defects in translation elongation but reveals somewhat higher occupancy by Ribo-T of the start codons and to a lesser extent stop codons, suggesting that subunit tethering mildly affects the initiation and termination stages of translation. Understanding limitations of Ribo-T system offers ways for its future development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Codon, Initiator / genetics
  • Codon, Initiator / metabolism
  • Escherichia coli / chemistry
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Protein Biosynthesis
  • RNA Processing, Post-Transcriptional
  • RNA, Bacterial / chemistry
  • RNA, Bacterial / genetics
  • RNA, Bacterial / metabolism
  • RNA, Ribosomal, 16S / chemistry
  • RNA, Ribosomal, 16S / genetics
  • RNA, Ribosomal, 16S / metabolism
  • RNA, Ribosomal, 23S / chemistry
  • RNA, Ribosomal, 23S / genetics
  • RNA, Ribosomal, 23S / metabolism
  • Ribosomal Proteins / genetics
  • Ribosomal Proteins / metabolism
  • Ribosome Subunits / chemistry*
  • Ribosome Subunits / genetics
  • Ribosome Subunits / metabolism*

Substances

  • Codon, Initiator
  • RNA, Bacterial
  • RNA, Ribosomal, 16S
  • RNA, Ribosomal, 23S
  • Ribosomal Proteins