Identification of regulatory targets for the bacterial Nus factor complex

Nat Commun. 2017 Dec 11;8(1):2027. doi: 10.1038/s41467-017-02124-9.

Abstract

Nus factors are broadly conserved across bacterial species, and are often essential for viability. A complex of five Nus factors (NusB, NusE, NusA, NusG and SuhB) is considered to be a dedicated regulator of ribosomal RNA folding, and has been shown to prevent Rho-dependent transcription termination. Here, we identify an additional cellular function for the Nus factor complex in Escherichia coli: repression of the Nus factor-encoding gene, suhB. This repression occurs primarily by translation inhibition, followed by Rho-dependent transcription termination. Thus, the Nus factor complex can prevent or promote Rho activity depending on the gene context. Conservation of putative NusB/E binding sites upstream of Nus factor genes suggests that Nus factor autoregulation occurs in many bacterial species. Additionally, many putative NusB/E binding sites are also found upstream of other genes in diverse species, and we demonstrate Nus factor regulation of one such gene in Citrobacter koseri. We conclude that Nus factors have an evolutionarily widespread regulatory function beyond ribosomal RNA, and that they are often autoregulatory.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Base Sequence
  • Binding Sites / genetics
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / genetics*
  • Escherichia coli Proteins / metabolism
  • Gene Expression Regulation, Bacterial*
  • Peptide Elongation Factors / genetics
  • Peptide Elongation Factors / metabolism
  • Phosphoric Monoester Hydrolases / genetics
  • Phosphoric Monoester Hydrolases / metabolism
  • Protein Binding
  • RNA Folding*
  • RNA, Ribosomal / chemistry*
  • RNA, Ribosomal / genetics
  • RNA, Ribosomal / metabolism
  • Ribosomal Proteins / genetics
  • Ribosomal Proteins / metabolism
  • Sequence Homology, Nucleic Acid
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcriptional Elongation Factors / genetics
  • Transcriptional Elongation Factors / metabolism

Substances

  • Escherichia coli Proteins
  • NusB protein, E coli
  • NusG protein, E coli
  • Peptide Elongation Factors
  • RNA, Ribosomal
  • Ribosomal Proteins
  • Transcription Factors
  • Transcriptional Elongation Factors
  • nusA protein, E coli
  • ribosomal protein S10
  • Phosphoric Monoester Hydrolases
  • SuhB protein, E coli