Bacterial Enhancer Binding Proteins-AAA+ Proteins in Transcription Activation

Biomolecules. 2020 Feb 25;10(3):351. doi: 10.3390/biom10030351.

Abstract

Bacterial enhancer-binding proteins (bEBPs) are specialised transcriptional activators. bEBPs are hexameric AAA+ ATPases and use ATPase activities to remodel RNA polymerase (RNAP) complexes that contain the major variant sigma factor, σ54 to convert the initial closed complex to the transcription competent open complex. Earlier crystal structures of AAA+ domains alone have led to proposals of how nucleotide-bound states are sensed and propagated to substrate interactions. Recently, the structure of the AAA+ domain of a bEBP bound to RNAP-σ54-promoter DNA was revealed. Together with structures of the closed complex, an intermediate state where DNA is partially loaded into the RNAP cleft and the open promoter complex, a mechanistic understanding of how bEBPs use ATP to activate transcription can now be proposed. This review summarises current structural models and the emerging understanding of how this special class of AAA+ proteins utilises ATPase activities to allow σ54-dependent transcription initiation.

Keywords: AAA+, bacterial enhancer-binding protein; DNA opening; gene transcription; transcription initiation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • AAA Proteins / chemistry
  • AAA Proteins / genetics
  • AAA Proteins / metabolism*
  • Adenosine Triphosphate / metabolism
  • Bacteria / chemistry
  • Bacteria / genetics*
  • Bacteria / metabolism
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Gene Expression Regulation, Bacterial*
  • Models, Molecular
  • Protein Conformation
  • Protein Multimerization
  • RNA Polymerase Sigma 54 / chemistry
  • RNA Polymerase Sigma 54 / genetics
  • RNA Polymerase Sigma 54 / metabolism
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcriptional Activation*

Substances

  • Bacterial Proteins
  • Transcription Factors
  • Adenosine Triphosphate
  • RNA Polymerase Sigma 54
  • AAA Proteins