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BP: Fachverband Biologische Physik

BP 29: Posters: Regulation

BP 29.9: Poster

Donnerstag, 29. März 2012, 17:30–19:30, Poster A

Nonenzymatic Replication of Polynucleotides — •Benedikt Obermayer¹, Kevin Leu², Rebecca Turk², Sudha Rajamani², Irene Chen² und Ulrich Gerland³ — ¹Department of Physics, Harvard University, Cambridge, USA — ²FAS Center for Systems Biology, Harvard University, Cambridge, USA — ³Ludwig-Maximilians-Universität München

In the early “RNA world” stage of life, RNA-like polynucleotides stored genetic information and catalyzed chemical reactions. Replication of such molecules suffers from high error rates, limiting the amount of information that can be reliably propagated. We study the fidelity of RNA and DNA replication using experimental non-enzymatic polymerization, and compare to lower bounds on these error rates calculated from a thermodynamic model. We find that RNA replication is intrinsically error-prone compared to DNA, suggesting that transitioning to DNA as genomic material could be of evolutionary advantage [1]. Moreover, we observe a strong context-dependence of polymerization rates, leading to a high probability of successive (cooperative) mutations and markedly slowed polymerization after mismatches. In an intriguing deviation from equilibrium expectations, these effects lead to a drastically lower effective error rate, alleviating its deleterious consequences.
[1] K. Leu, B. Obermayer, S. Rajamani, U. Gerland, I. A. Chen, Nucl. Acids Res. 39:8135 (2011)