Dresden 2017 – scientific programme

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BP: Fachverband Biologische Physik

BP 20: Posters - Physics of the Genesis of Life (Focus Session)

BP 20.1: Poster

Tuesday, March 21, 2017, 14:00–16:00, P1A

Chemically Driven Ligation Chain Reaction - Towards Protein-free Hypercycles in Sequence Space? — •Stefanie Leiner, Evgeniia Edeleva, and Dieter Braun — Systems Biophysics, Physics Department, LMU Munich, Germany

Which mechanism could have fostered the stable emergence of functional sequences for an RNA world? Eigen's hypercycles suggests that cooperating replication leads to hyperexponential selection.

Hypercycle dynamics can be implemented via competitive oligonucleotide ligation in long-term experiments. Under serial dilution, to mimic molecule degradation, this process enhances the replication of majority sequences and allows their emergence from a random sequence pool. Hyperexponential replication arises from the competitive binding kinetics of ligation: oligonucleotides with long-range sequence correlations ligate faster by cooperative hybridization. The mechanism requires thermal cycling - a non-equilibrium boundary condition that could be provided together with accumulation by heat flow across pores of rock [1].

Our investigations show that EDC can be used in an in-situ activated ligation reaction with 80 % yield for temperatures below ~40 °C [2][3]. We show preliminary results towards protein-free hypercycles in sequence space.

[1] S. Toyabe, D. Braun, under review. [2] M. Jauker et al. Angew. Chem. Int. Ed. 2015, 54, 14559-14563. [3] Taran et al. J. Sys. Chem. 2010, 1:9, 1-16.