Published In

Journal of Biological Chemistry

Document Type

Article

Publication Date

2-11-2023

Subjects

DNA replication -- Genomes

Abstract

Accurately completing DNA replication when two forks converge is essential to genomic stability. The RecBCD helicase–nuclease complex plays a central role in completion by promoting resection and joining of the excess DNA created when replisomes converge. chi sequences alter RecBCD activity and localize with crossover hotspots during sexual events in bacteria, yet their functional role during chromosome replication remains unknown. Here, we use two-dimensional agarose gel analysis to show that chi induces replication on substrates containing convergent forks. The induced replication is processive but uncoupled with respect to leading and lagging strand synthesis and can be suppressed by ter sites which limit replisome progression. Our observations demonstrate that convergent replisomes create a substrate that is processed by RecBCD and that chi, when encountered, switches RecBCD from a degradative to replicative function. We propose that chi serves to functionally differentiate DNA ends created during completion, which require degradation, from those created by chromosomal double-strand breaks, which require resynthesis.

Rights

© 2023 THE AUTHORS. Published by Elsevier Inc on behalf of American Society for Biochemistry and Molecular Biology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Locate the Document

https://doi.org/10.1016/j.jbc.2023.103013

DOI

10.1016/j.jbc.2023.103013

Persistent Identifier

https://archives.pdx.edu/ds/psu/39741

Download

Included in

Biology Commons

Share

COinS