Optimal exploitation of the expanding database of sequences requires rapid finding and folding of RNAs. Methods are reviewed that automate folding and discovery of RNAs with algorithms that couple thermodynamics with chemical mapping, NMR, and/or sequence comparison. New functional noncoding RNAs in genome sequences can be found by combining sequence comparison with the assumption that function...

We study the force-induced unfolding of random disordered RNA or single-stranded DNA polymers. The system undergoes a second-order phase transition from a collapsed globular phase at low forces to an extensive necklace phase with a macroscopic end-to-end distance at high forces. At low temperatures, the sequence inhomogeneities modify the critical behaviour. We provide numerical evidence for th...

We report a method for predicting the most stable secondary structure of RNA from its primary sequence of nucleotides. The technique consists of a series of three computer programs interfaced to take the nucleotide sequence of any RNA and (a) list all possible helical regions, using modified Watson-Crick base-pairing rules; (b) create all possible secondary structures by forming permutations of...

RNA structure formation is hierarchical and, therefore, secondary structure, the sum of canonical base-pairs, can generally be predicted without knowledge of the three-dimensional structure. Secondary structure prediction algorithms evolved from predicting a single, lowest free energy structure to their current state where statistics can be determined from the thermodynamic ensemble. This artic...

Since the last ten years several tools have been proposed for RNA secondary structure pairwise comparison. These tools use different models (ordered tree or forest, arc annotated sequence, multi-level tree) and methods (edit distance, alignment). We present a first benchmark on these tools. For various RNA families, we built two sets of secondary structures. The first, called the reference set,...

Telomerase is a ribonucleoprotein enzyme that maintains telomere length by adding telomeric sequence repeats onto chromosome ends. The essential RNA component of telomerase provides the template for telomeric repeat synthesis. To determine the secondary structure of vertebrate telomerase RNA, 32 new telomerase RNA genes were cloned and sequenced from a variety of vertebrate species including 18...

A secondary structure model for 16S ribosomal RNA which is based on available chemical, enzymatic, and comparative sequence data shows good agreement between constraints dictated by the model and a wide variety of experimental observations. The four major structural domains created by the base-pairing scheme correspond closely to RNA fragments isolated after nuclease digestion in the presence o...

Here we discuss recent developments in predicting RNA secondary structure, giving an overview of methods used, including energy minimization and Boltzmann sampling, a probabilistic approach, and the use of fragment libraries generated from high resolution three-dimensional RNA crystal structures. An example for each of these three methods is discussed in detail (namely Sfold, CONTRAfold and MC-...

In this paper, we propose a new layout algorithm that draws the secondary structure of a Ribonucleic Acid (RNA) automatically according to some of the biologists’ aesthetic criteria. Such layout insures that two equivalent structures (or sub-structures) are drawn in a same and planar way. In order to allow a visual comparison of two RNAs, we use an heuristic that places the biggest similar part...

Many RNA structures are assembled from a collection of RNA motifs, which appear repeatedly and in various combinations. Identification of RNA structural motifs will enhance our understanding of RNA structures and functions. Searching for secondary structural patterns in sequence databases is the basic technique and fundamental problem for extracting and identifying such motifs. A number of algo...