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.
Shivashankar
G V
GV
Center for Studies in Physics and Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA. shiva@athena.rockfeller.edu
Feingold
M
M
Krichevsky
O
O
Libchaber
A
A
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