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Biomedical subjects

J Cupal

Publications and source records attributed to J Cupal.

3 recordsLinked to original sources

RNA shape space topology.

The distinction between continuous and discontinuous transitions is a long-standing problem in the theory of evolution. Because continuity is a topological property, we present a formalism that treats the space of phenotypes as a (finite) topological space, with a topology that is derived from the probabilities with which one phenotype is accessible from another through changes at the genotypic level. The shape space of RNA secondary structures is used to illustrate this approach. We show that evolutionary trajectories are continuous if and only if they follow connected paths in phenotype space.

Models, Genetic↗

Density of states, metastable states, and saddle points exploring the energy landscape of an RNA molecule.

Detailed knowledge of the energy landscape of a biopolymer molecule is a prerequisite for understanding its folding kinetics and its final spatial structure. In the case of RNA we consider the energy landscape defined on the set of all secondary structures that can be formed by a given sequence. We show that the exploration of this energy landscapes is computationally feasible. For this purpose we present a recursive algorithm for computing the complete density of states and discuss its application to tRNA sequences. For shorter sequences a more detailed analysis of the energy surface is possible using a complete list of all secondary structures. In this case we identify metastable states and the saddle points that connect them.

Algorithms↗