Crystal structure of a bacterial RNA polymerase holoenzyme at 2.6. Å resolution

Academic Article

Abstract

  • In bacteria, the binding of a single protein, the initiation factor σ, to a multi-subunit RNA polymerase core enzyme results in the formation of a holoenzyme, the active form of RNA polymerase essential for transcription initiation. Here we report the crystal structure of a bacterial RNA polymerase holoenzyme from Thermus thermophilus at 2.6 Å resolution. In the structure, two amino-terminal domains of the σ subunit form a V-shaped structure near the opening of the upstream DNA-binding channel of the active site cleft. The carboxy-terminal domain of σ is near the outlet of the RNA-exit channel, about 57 Å from the N-terminal domains. The extended linker domain forms a hairpin protruding into the active site cleft, then stretching through the RNA-exit channel to connect the N- and C-terminal domains. The holoenzyme structure provides insight into the structural organization of transcription intermediate complexes and into the mechanism of transcription initiation.
  • Published In

  • Nature  Journal
  • Digital Object Identifier (doi)

    Author List

  • Vassylyev DG; Sekine SI; Yokoyama S
  • Start Page

  • 712
  • End Page

  • 719
  • Volume

  • 417
  • Issue

  • 6890