Role of XerCD in release of over-replicated DNA through Outer Membrane Vesicles inEscherichia coli

Abstract

AbstractOuter membrane vesicles (OMVs) are universally produced by prokaryotes and play important roles in symbiotic and pathogenic interactions. Here we show that the GammaproteobacteriumEscherichia coliproduces OMVs that contain DNA enriched for the region around the terminus of replicationter, and specifically for the recognition sequencedifof the two site-specific recombinases XerCD, similar to OMVs from the AlphaproteobacteriumDinoroseobacter shibae. In deletion mutants ofxerCorxerD, the enriched region aroundterbecomes broader while the peak directly at thedifsequence itself is reduced.ImportanceImprecise termination of replication can lead to over-replicated parts of bacterial chromosomes that have to be excised and removed from the dividing cell. The underlying mechanism is so far poorly understood. Our data suggest a conserved mechanism for repair and removal of over-replicated DNA through outer membrane vesicles and an active role of the site-specific XerCD recombinase complex therein.