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Updated: May 31, 2026

Desthiobiotin-Streptavidin-Affinity Mediated Purification of RNA-Interacting Proteins in Mesothelioma Cells
Published on: April 25, 2018
Human senataxin resolves RNA/DNA hybrids formed at transcriptional pause sites to promote Xrn2-dependent termination
Konstantina Skourti-Stathaki1, Nicholas J Proudfoot, Natalia Gromak
1Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK.
Abstract:
We present a molecular dissection of pause site-dependent transcriptional termination for mammalian RNA polymerase II (Pol II)-transcribed genes. We show that nascent transcripts form RNA/DNA hybrid structures (R-loops) behind elongating Pol II and are especially prevalent over G-rich pause sites positioned downstream of gene poly(A) signals. Senataxin, a helicase protein associated with AOA2/ALS4 neurodegenerative disorders, acts to resolve these R-loop structures and by so doing allows access of the 5'-3' exonuclease Xrn2 at 3' cleavage poly(A) sites. This affords 3' transcript degradation and consequent Pol II termination. In effect, R-loops formed over G-rich pause sites, followed by their resolution by senataxin, are key steps in the termination process.
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