The extruded non-template strand determines the architecture of R-loops.

ABSTRACT: Three-stranded R-loop structures have been associated with genomic instability phenotypes. What underlies their wide-ranging effects on genome stability remains poorly understood. Here we combined biochemical and atomic force microscopy approaches with single molecule R-loop footprinting to demonstrate that R-loops formed at the model Airn locus in vitro adopt a defined set of three-dimensional conformations characterized by distinct shapes and volumes, which we call R-loop objects. Interestingly, we show that these R-loop objects impose specific physical constraints on the DNA, as revealed by the presence of stereotypical angles in the surrounding DNA. Biochemical probing and mutagenesis experiments revealed that the formation of R-loop objects at Airn is dictated by the extruded non-temp

SUBMITTER: Carrasco-Salas Y 

PROVIDER: S-EPMC6648340 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature