Dresden 2014 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 2: DNA/RNA and related enzymes

BP 2.4: Vortrag

Montag, 31. März 2014, 10:15–10:30, ZEU 250

Extreme polymerization and aggregation of DNA/RNA in thermal traps — •Christof Mast¹, Severin Schink², Moritz Kreysing¹, Urlich Gerland², and Dieter Braun¹ — ¹Systems Biophysics, Physics Department, Center for Nanoscience, LMU Munich, Germany — ²Arnold-Sommerfeld-Center for Theoretical Physics and Center for Nanoscience, LMU Munich, Germany

Biopolymers like RNA, DNA and proteins are the fundamental actors in all life on earth. It is however unclear, how the first long RNA polymers with enzymatic activity could arise in a prebiotic scenario: Even in millimolar concentrations, ribonucleic acids only polymerize to short strands with a length of 20 bases. We demonstrate how a simple thermal gradient in a hydrothermal pore-like geometry is able to trap longer polymers exponentially better than shorter polymers. Polymerization leads to even longer polymers due to the increased total mass in the trapping center. Polymerization and thermal trapping are mutually self-enhancing. This process is described by an experimentally supported theory of trapped polymerization. Theoretical extrapolation to RNA-world conditions shows that a pore height of 5 cm and a temperature difference of 10 K are sufficient to form RNA polymers longer than the shortest RNA based replicator. Thermal traps also support the sequence specific formation of large aggregates made by the reversible polymerization of sticky-ended dsDNA. The melting temperature of the aggregates and the sticky ends match. No aggregates were found with non-polymerizing dsDNA pieces or without thermal trapping which therefore acts as a highly sequence selective process.