Berlin 2012 – scientific programme

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BP: Fachverband Biologische Physik

BP 20: Regulation

BP 20.11: Talk

Thursday, March 29, 2012, 12:30–12:45, H 1058

Physical limits of replication accuracy under nonequilibrium prebiotic conditions — Benedikt Obermayer¹ and •Ulrich Gerland² — ¹Department of Physics, Harvard University, USA — ²Department of Physics, LMU München, Germany

Without the help of kinetic proofreading enzymes that can employ chemical energy to improve the accuracy of template-directed replication processes, the mutation rate of these processes is limited from below by fundamental principles of statistical physics. This limit is particularly relevant for prebiotic copying processes of a polynucleotide such as RNA, before the advent of kinetic proofreading enzymes. Under equilibrium conditions, the limit is directly related to a free energy of discrimination related to the difference in the thermodynamic stability of the correct and the incorrect products. However, when the system in which the copying process takes place is not in equilibrium, the lower physical limit on the mutation rate can be changed. We discuss a situation where physical nonequilibrium can improve the replication accuracy, optimize the conditions of the system, and relate our scenario to recent experiments on non-enzymatic template-directed copying processes.