Transcription blockage by bulky end termini at single-strand breaks in the DNA template: differential effects of 5' and 3' adducts.

ABSTRACT: RNA polymerases from phage-infected bacteria and mammalian cells have been shown to bypass single-strand breaks (SSBs) with a single-nucleotide gap in the template DNA strand during transcription elongation; however, the SSB bypass efficiency varies significantly depending upon the backbone end chemistries at the break. Using a reconstituted T7 phage transcription system (T7 RNAP) and RNA polymerase II (RNAPII) in HeLa cell nuclear extracts, we observe a slight reduction in the level of transcription arrest at SSBs with no gap as compared to those with a single-nucleotide gap. We have shown that biotin and carbon-chain moieties linked to the 3' side, and in select cases the 5' side, of an SSB in the template strand strongly increase the level of transcription arrest when compared to unmodi

SUBMITTER: Neil AJ 

PROVIDER: S-EPMC4153415 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature