Oct 26, 2018

RNA polymerase clamp movement aids dissociation from DNA but is not required for RNA release at intrinsic terminators

BioRxiv : the Preprint Server for Biology
Michael J BellecourtRobert Landick


In bacteria, viability requires efficient disassembly of elongating transcription complexes (ECs) in a 2-3 nucleotide window after transcription of multiple kilobase pairs of DNA. Intrinsic terminator signals trigger pausing over weak RNA-DNA base pairs followed by formation of a strong, GC-rich stem-loop structure in the RNA exit channel of RNA polymerase (RNAP) to inactivate nucleotide addition and induce dissociation of RNA and RNAP from DNA. Although study of RNA and DNA movements during termination has produced multiple models, the roles of RNAP conformational changes remain poorly defined. RNAP contains a clamp domain that closes around the nucleic-acid scaffold during transcription initiation and can be displaced by either swiveling or opening motions. Clamp displacement is proposed to promote termination by releasing RNAP-nucleic acid contacts. We developed a cysteine-crosslinking assay to constrain clamp movements and study effects on intrinsic termination. We found that biasing the clamp into different conformations perturbed termination efficiency, but that these perturbations were due primarily to changes in elongation rate, not the competing rate at which the EC commits to termination. After commitment, however, in...Continue Reading

  • References
  • Citations


  • We're still populating references for this paper, please check back later.
  • References
  • Citations


  • This paper may not have been cited yet.

Mentioned in this Paper

RNA Polymerase II
DNA Repair
DNA-Directed RNA Polymerase
RNA Polymerase Assembly Pathway
Complex (molecular entity)
Transcription, Genetic
Transcription Initiation
Intrinsic Factor Assay
PDZK1 gene

About this Paper

Related Feeds

BioRxiv & MedRxiv Preprints

BioRxiv and MedRxiv are the preprint servers for biology and health sciences respectively, operated by Cold Spring Harbor Laboratory. Here are the latest preprint articles (which are not peer-reviewed) from BioRxiv and MedRxiv.