Impairment of transcription elongation by R-loops in vitro.
Transcription elongation causes a local change in DNA superhelicity. An excess of negative supercoiling may lead to opening of DNA strands that could allow formation of R-loops. In yeast, mutants of the THO complex are impaired in transcription elongation and this defect has been linked to co-transcriptional formation of R-loops, which could constitute roadblocks for RNA polymerases. In this study, we found that stably formed 300-nt long DNA-RNA hybrids in a negatively supercoiled transcription template reduced the efficiency of transcription elongation by half, providing a first experimental evidence that transcription elongation is impaired by R-loops in vitro.
Tous
Cristina
C
Departamento de Genética, Facultad de Biología, and Departamento de Biología Molecular, CABIMER, CSIC-Universidad de Sevilla, Av. Américo Vespucio s/n, 41092 Sevilla, Spain.
Aguilera
Andrés
A
D004249:DNA Damage / Q000235:genetics*; D004271:DNA, Fungal / Q000737:chemistry* / Q000235:genetics*; D012331:RNA, Fungal / Q000737:chemistry* / Q000235:genetics*; D013329:Structure-Activity Relationship; D014158:Transcription, Genetic / Q000235:genetics*; D035602:Transcriptional Elongation Factors / Q000737:chemistry / Q000235:genetics*
D004271:DNA, Fungal; D012331:RNA, Fungal; D035602:Transcriptional Elongation Factors