RecA polymerization on double-stranded DNA by using single-molecule manipulation: the role of ATP hydrolysis.
The polymerization of RecA on individual double-stranded DNA molecules is studied. A linear DNA (lambda DNA, 48.5 Kb), anchored at one end to a cover glass and at the other end to an optically trapped 3-micrometers diameter polystyrene bead, serves as a template. The elongation caused by RecA assembly is measured in the presence of ATP and ATP[gammaS]. By using force extension and hydrodynamic recoil, a value of the persistence length of the RecA-DNA complex is obtained. In the presence of ATP, the polymer length is unstable, first growing to saturation and then decreasing. This suggests a transient dynamics of association and dissociation for RecA on a double-stranded DNA, the process being controlled by ATP hydrolysis. Part of this dynamics is suppressed in the presence of ATP[gammaS], leading to a stabilized RecA-DNA complex. A one-dimensional nucleation and growth model is presented that may account for the protein assembly.
Center for Studies in Physics and Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA. shiva@athena.rockfeller.edu
G V
GV
Shivashankar
M
M
Feingold
O
O
Krichevsky
A
A
Libchaber
D000255:Adenosine Triphosphate / Q000378:metabolism*; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D011137:Polystyrenes; D011485:Protein Binding; D011938:Rec A Recombinases / Q000737:chemistry* / Q000378:metabolism*
D011137:Polystyrenes; D000255:Adenosine Triphosphate; D004247:DNA; D011938:Rec A Recombinases