Partitioning of plasmid R1. The ParM protein exhibits ATPase activity and interacts with the centromere-like ParR-parC complex

RB Jensen, K Gerdes

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100 Citationer (Scopus)

Abstract

The parA system of plasmid R1 consists of hive genes, parM and parR, and a cis-acting centromere-like site parC. The ParM protein exhibits similarity with a superfamily of ATPases that includes actin, hsp70 and hexokinase. ParM was purified to near-homogeneity and assayed for in vitro ATPase activity. The wild-type ParM protein was found to posses ATPase activity. Mutant ParM derivatives that exhibited decreased in vitro ATPase activity were non-fuctional in vivo, indicating that the ATP turnover by ParM is essential for correct plasmid partitioning. The mutant ParM proteins exhibited trans-dominance, suggesting that ParM participates as a structural component of the partitioning apparatus. The ATPase activity of ParM was activated slightly by the presence of ParR and activated to a much greater extent when ParR was bound to the centromere-like parC region. An analysis using the yeast two-hybrid system indicated that ParM and ParR interact, and demonstrated that ParR interacts with itself. Thus our results suggest a direct interaction of ParM and ParR at the natural partition site parC, and that the ATPase activity of ParM is specifically stimulated by this interaction. (C) 1997 Academic Press Limited.
OriginalsprogEngelsk
TidsskriftJournal of Molecular Biology
Vol/bind269
Udgave nummer4
Sider (fra-til)505-513
Antal sider9
ISSN0022-2836
DOI
StatusUdgivet - 1997
Udgivet eksterntJa

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