Periodic conformational changes in rRNA: monitoring the dynamics of translating ribosomes

Mol Cell. 2000 Jul;6(1):159-71.


In protein synthesis, a tRNA transits the ribosome via consecutive binding to the A (acceptor), P (peptidyl), and E (exit) site; these tRNA movements are catalyzed by elongation factor G (EF-G) and GTP. Site-specific Pb2+ cleavage was applied to trace tertiary alterations in tRNA and all rRNAs on pre- and posttranslocational ribosomes. The cleavage pattern of deacylated tRNA and AcPhe-tRNA changed individually upon binding to the ribosome; however, these different conformations were unaffected by translocation. On the other hand, translocation affects 23S rRNA structure. Significantly, the Pb2+ cleavage pattern near the peptidyl transferase center was different before and after translocation. This structural rearrangement emerged periodically during elongation, thus providing evidence for a dynamic and mobile role of 23S rRNA in translocation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Protein Biosynthesis*
  • RNA, Bacterial / chemistry
  • RNA, Bacterial / genetics
  • RNA, Bacterial / metabolism
  • RNA, Ribosomal / chemistry*
  • RNA, Ribosomal / genetics*
  • RNA, Ribosomal / metabolism
  • RNA, Ribosomal, 23S / chemistry
  • RNA, Ribosomal, 23S / genetics
  • RNA, Ribosomal, 23S / metabolism
  • RNA, Transfer, Phe / chemistry
  • RNA, Transfer, Phe / genetics
  • RNA, Transfer, Phe / metabolism
  • Ribosomes / metabolism*


  • RNA, Bacterial
  • RNA, Ribosomal
  • RNA, Ribosomal, 23S
  • RNA, Transfer, Phe