Mechanisms of Bacterial Transcription Termination: All Good Things Must End

Annu Rev Biochem. 2016 Jun 2;85:319-47. doi: 10.1146/annurev-biochem-060815-014844. Epub 2016 Mar 17.

Abstract

Transcript termination is essential for accurate gene expression and the removal of RNA polymerase (RNAP) at the ends of transcription units. In bacteria, two mechanisms are responsible for proper transcript termination: intrinsic termination and Rho-dependent termination. Intrinsic termination is mediated by signals directly encoded within the DNA template and nascent RNA, whereas Rho-dependent termination relies upon the adenosine triphosphate-dependent RNA translocase Rho, which binds nascent RNA and dissociates the elongation complex. Although significant progress has been made in understanding these pathways, fundamental details remain undetermined. Among those that remain unresolved are the existence of an inactivated intermediate in the intrinsic termination pathway, the role of Rho-RNAP interactions in Rho-dependent termination, and the mechanisms by which accessory factors and nucleoid-associated proteins affect termination. We describe current knowledge, discuss key outstanding questions, and highlight the importance of defining the structural rearrangements of RNAP that are involved in the two mechanisms of transcript termination.

Keywords: H-NS; NusG; RNA hairpin; RNA polymerase; Rho-dependent termination; intrinsic termination.

Publication types

  • Review

MeSH terms

  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • DNA, Bacterial / metabolism
  • DNA-Directed RNA Polymerases / chemistry
  • DNA-Directed RNA Polymerases / genetics*
  • DNA-Directed RNA Polymerases / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / genetics*
  • Escherichia coli Proteins / metabolism
  • Kinetics
  • Models, Molecular
  • Nucleic Acid Conformation
  • Peptide Elongation Factors / genetics*
  • Peptide Elongation Factors / metabolism
  • Protein Binding
  • Protein Transport
  • RNA, Bacterial / chemistry
  • RNA, Bacterial / genetics
  • RNA, Bacterial / metabolism
  • Rho Factor / genetics*
  • Rho Factor / metabolism
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transcription Termination, Genetic*

Substances

  • DNA, Bacterial
  • Escherichia coli Proteins
  • NusG protein, E coli
  • Peptide Elongation Factors
  • RNA, Bacterial
  • Rho Factor
  • Transcription Factors
  • DNA-Directed RNA Polymerases