High-fidelity DNA sensing by protein binding fluctuations.
One of the major functions of RecA protein in the cell is to bind single-stranded DNA exposed upon damage, thereby triggering the SOS repair response. We present fluorescence anisotropy measurements at the binding onset, showing enhanced DNA length discrimination induced by adenosine triphosphate consumption. Our model explains the observed DNA length sensing as an outcome of out-of-equilibrium binding fluctuations, reminiscent of microtubule dynamic instability. The cascade architecture of the binding fluctuations is a generalization of the kinetic proofreading mechanism. Enhancement of precision by an irreversible multistage pathway is a possible design principle in the noisy biological environment.
Tlusty
Tsvi
T
Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, Israel 76100.
Bar-Ziv
Roy
R
Libchaber
Albert
A
D000255:Adenosine Triphosphate / Q000737:chemistry*; D001665:Binding Sites; D015374:Biosensing Techniques / Q000379:methods*; D003198:Computer Simulation; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry; D004789:Enzyme Activation; D008956:Models, Chemical; D015233:Models, Statistical; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D011938:Rec A Recombinases / Q000737:chemistry*
D004268:DNA-Binding Proteins; D000255:Adenosine Triphosphate; D004247:DNA; D011938:Rec A Recombinases