Skip to main content
padlock icon - secure page this page is secure

Free Content Nus transcription elongation factors and RNase III modulate small ribosome subunit biogenesis in Escherichia coli

Download Article:
 Download
(PDF)
 
Summary

Escherichia coli NusA and NusB proteins bind specific sites, such as those in the leader and spacer sequences that flank the 16S region of the ribosomal RNA transcript, forming a complex with RNA polymerase that suppresses Rho‐dependent transcription termination. Although antitermination has long been the accepted role for Nus factors in rRNA synthesis, we propose that another major role for the Nus‐modified transcription complex in rrn operons is as an RNA chaperone insuring co‐ordination of 16S rRNA folding and RNase III processing that results in production of proper 30S ribosome subunits. This contrarian proposal is based on our studies of nusA and nusB cold‐sensitive mutations that have altered translation and at low temperature accumulate 30S subunit precursors. Both phenotypes are suppressed by deletion of RNase III. We argue that these results are consistent with the idea that the nus mutations cause altered rRNA folding that leads to abnormal 30S subunits and slow translation. According to this idea, functional Nus proteins stabilize an RNA loop between their binding sites in the 5′ RNA leader and on the transcribing RNA polymerase, providing a topological constraint on the RNA that aids normal rRNA folding and processing.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Document Type: Research Article

Publication date: January 1, 2013

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more