Multiple enzymatic activities of ParB/Srx superfamily mediate sexual conflict among conjugative plasmids.

ABSTRACT: Conjugative plasmids are typically locked in intergenomic and sexual conflicts with co-resident rivals, whose translocation they block using fertility inhibition factors (FINs). We describe here the first crystal structure of an enigmatic FIN Osa deployed by the proteobacterial plasmid pSa. Osa contains a catalytically active version of the ParB/Sulfiredoxin fold with both ATPase and DNase activity, the latter being regulated by an ATP-dependent switch. Using the Agrobacterium tumefaciens VirB/D4 type IV secretion system (T4SS), a relative of the conjugative T4SS, we demonstrate that catalytically active Osa blocks T-DNA transfer into plants. With a partially reconstituted T4SS in vitro, we show that Osa degrades T-DNA in the T-DNA-VirD2 complex before its translocation. Further, we presen

SUBMITTER: Maindola P 

PROVIDER: S-EPMC4241021 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature