Analysis of the PcrA-RNA polymerase complex reveals a helicase interaction motif and a role for PcrA/UvrD helicase in the suppression of R-loops

eLife

James R Ault¹  Frank Sobott¹  Mark S Dillingham²  Nigel J Savery²  Inigo Urrutia-Irazabal² 

[1] Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom;DNA:Protein Interactions Unit, School of Biochemistry, University of Bristol. Biomedical Sciences Building, University Walk, Bristol, United Kingdom;

关键词: helicase;    transcription;    R-loop;    replication-transcription conflict;    HDX-MS;    DNA repair;   

DOI  :  10.7554/eLife.68829

来源: DOAJ

【 摘 要 】

The PcrA/UvrD helicase binds directly to RNA polymerase (RNAP) but the structural basis for this interaction and its functional significance have remained unclear. In this work, we used biochemical assays and hydrogen-deuterium exchange coupled to mass spectrometry to study the PcrA-RNAP complex. We find that PcrA binds tightly to a transcription elongation complex in a manner dependent on protein:protein interaction with the conserved PcrA C-terminal Tudor domain. The helicase binds predominantly to two positions on the surface of RNAP. The PcrA C-terminal domain engages a conserved region in a lineage-specific insert within the β subunit which we identify as a helicase interaction motif present in many other PcrA partner proteins, including the nucleotide excision repair factor UvrB. The catalytic core of the helicase binds near the RNA and DNA exit channels and blocking PcrA activity in vivo leads to the accumulation of R-loops. We propose a role for PcrA as an R-loop suppression factor that helps to minimize conflicts between transcription and other processes on DNA including replication.

【 授权许可】

Unknown