Streptococcus pyogenes pSM19035 requires dynamic assembly of ATP-bound ParA and ParB on parS DNA during plasmid segregation.

ABSTRACT: The accurate partitioning of Firmicute plasmid pSM19035 at cell division depends on ATP binding and hydrolysis by homodimeric ATPase delta(2) (ParA) and binding of omega(2) (ParB) to its cognate parS DNA. The 1.83 A resolution crystal structure of delta(2) in a complex with non-hydrolyzable ATPgammaS reveals a unique ParA dimer assembly that permits nucleotide exchange without requiring dissociation into monomers. In vitro, delta(2) had minimal ATPase activity in the absence of omega(2) and parS DNA. However, stoichiometric amounts of omega(2) and parS DNA stimulated the delta(2) ATPase activity and mediated plasmid pairing, whereas at high (4:1) omega(2) : delta(2) ratios, stimulation of the ATPase activity was reduced and delta(2) polymerized onto DNA. Stimulation of the delta(2) ATPase

SUBMITTER: Pratto F 

PROVIDER: S-EPMC2441792 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature