4e03

Publication Abstract from PubMed

Segregation of the bacterial multidrug resistance plasmid TP228 requires the centromere-binding protein, ParG the parH centromere and the Walker-box ATPase, ParF. The cycling of ParF between ADP and ATP bound states drives TP228 partition; ATP binding stimulates ParF polymerization, which is essential for segregation while ADP binding antagonizes polymerization and inhibits DNA partition. The molecular mechanism involved in this adenine nucleotide switch is unclear. Moreover, it is unknown how any Walker-box protein polymerizes in an ATP-dependent manner. Here we describe multiple ParF structures in ADP and AMPPCP bound states. ParF-ADP is monomeric but dimerizes when complexed with AMPPCP. Strikingly, in ParF-AMPPCP structures, the dimers interact to create dimer-of-dimers units that generate a specific linear filament. Mutation of interface residues prevents both polymerization and DNA segregation in vivo. Thus, these data reveal the unique mechanism by which a Walker-box protein forms polymers that involves the generation of ATP-induced dimer-of-dimer building blocks.

Structural mechanism of ATP induced polymerization of the partition factor ParF: implications for DNA segregation.,Schumacher MA, Ye Q, Barge MT, Zampini M, Barilla D, Hayes F J Biol Chem. 2012 Jun 6. PMID:22674577^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.