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Dynamic Processing of Displacement Loops during Recombinational DNA Repair.

ABSTRACT: Displacement loops (D-loops) are pivotal intermediates of homologous recombination (HR), a universal DNA double strand break (DSB) repair pathway. We developed a versatile assay for the physical detection of D-loops in vivo, which enabled studying the kinetics of their formation and defining the activities controlling their metabolism. Nascent D-loops are detected within 2 h of DSB formation and extended in a delayed fashion in a genetic system designed to preclude downstream repair steps. The majority of nascent D-loops are disrupted by two pathways: one supported by the Srs2 helicase and the other by the Mph1 helicase and the Sgs1-Top3-Rmi1 helicase-topoisomerase complex. Both pathways operate without significant overlap and are delineated by the Rad54 paralog Rdh54 in an ATPase-independent fashion. This study uncovers a layer of quality control of HR relying on nascent D-loop dynamics.

SUBMITTER: Piazza A

PROVIDER: S-EPMC6532985 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Dynamic Processing of Displacement Loops during Recombinational DNA Repair.

Piazza Aurèle A Shah Shanaya Shital SS Wright William Douglass WD Gore Steven K SK Koszul Romain R Heyer Wolf-Dietrich WD

Molecular cell 20190205 6

Displacement loops (D-loops) are pivotal intermediates of homologous recombination (HR), a universal DNA double strand break (DSB) repair pathway. We developed a versatile assay for the physical detection of D-loops in vivo, which enabled studying the kinetics of their formation and defining the activities controlling their metabolism. Nascent D-loops are detected within 2 h of DSB formation and extended in a delayed fashion in a genetic system designed to preclude downstream repair steps. The m ...[more]

PMID: 30737186

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