RNA folding is viewed as a map assigning secondary structures to sequences. At fixed chain length the number of sequences exceeds by far the number of structures. Frequencies of structures are highly non-uniform: we find relatively few common and many rare ones. Using an algorithm for inverse...

Secondary structures of polynucleotides can be view as a certain class of planar vertex-labeled graphs. We construct recursion formulae enumerating various sub-classes of these graphs as well as certain structural elements (sub-graphs). First order asymptotics are derived and their dependence on...

The heights of energy barriers separating two (macro-)states are useful for estimating transition frequencies. In non-degenerate landscapes the decomposition of a landscape into basins surrounding local minima connected by saddle points is straightforward and yields a useful definition of...

Computer codes for computation and comparison of RNA secondary structures, the {\tt Vienna RNA package}, are presented, that are based on dynamic programming algorithms and aim at predictions of structures with minimum free energies as well as at computations of the equilibrium partition...

Algorithms predicting RNA secondary structures based on different folding criteria---minimum free energy (mfe), kinetic folding (kin), maximum matching (mm)---and different parameter sets are studied systematically. Two base pairing alphabets were used: the binary GC and the natural four-letter...

We propose a new method for detecting conserved RNA secondary structures in a family of related RNA sequences. Our method is based on a combination of thermodynamic structure prediction and phylogenetic comparison. In contrast to purely phylogenetic methods, our algorithm can be used for small...

Secondary structure prediction is a standard tool in the analysis of RNA sequences. The prediction of RNA secondary structures is inherently non-local. This makes the analysis of long sequences (more than 4000 nucleotides) infeasible on present-day workstations. An implementation of the...

Background: Protein space is explored by means of an inverse folding procedure that makes use of knowledge-based potentials of mean force. <p> Results: Computer simulations indicate that amino acid sequences folding into a common shape are distributed homogeneously forming extended percolating...</p>

Knowledge-based potentials can be used to decide whether an amino acid sequence is likely to fold into a prescribed native protein structure. We use this idea to survey the sequence-structure relations in protein space. In particular, we test the following two propositions which were found to be...

Global relations between RNA sequences and secondary structures are understood as mappings from sequence space into shape space. These mappings are investigated by exhaustive folding of all GC and AU sequences with chain lengths up to 30. The technique of tried is used for economic data storage...