A pseudoknot is an intra-molecular structure formed primarily in RNA strands and much research has been done to predict efficiently pseudoknot structures in RNA. We define an operation that generates all pseudoknots from a given sequence and consider algorithmic and language theoretic properties of the operation. We give an efficient algorithm to decide whether a given string is a pseudoknot of...

The PK1 pseudoknot is a well-characterized super secondary structure from Aquifex aeolicus transfer-messenger RNA that participates in the ribosomal trans-translation rescue mechanism. Extensive all-atom molecular dynamics simulations were conducted across worldwide distributed computing network to study folding, unfolding, misfolding, and conformational plasticity of twenty-two nucleotide pseu...

NMR methods were used to investigate a series of mutants of the pseudoknot within the gene 32 messenger RNA of bacteriophage T2, for the purpose of investigating the range of sequences, stem and loop lengths that can form a similar pseudoknot structure. This information is of particular relevance since the T2 pseudoknot has been considered a representative of a large family of RNA pseudoknots r...

Telomerase ribonucleoprotein (RNP) employs an RNA subunit to template the addition of telomeric repeats onto chromosome ends. Previous studies have suggested that a region of the RNA downstream of the template may be important for telomerase activity and that the region could fold into a pseudoknot. Whether the pseudoknot motif is formed in the active telomerase RNP and what its functional role...

The structure of a 34-nucleotide RNA pseudoknot that causes efficient -1 frameshifting in the messenger RNA of mouse mammary tumor virus has been investigated by NMR. Spectral assignment of the pseudoknot was facilitated by comparative NMR studies on the pseudoknot and on two smaller hairpin RNAs, and by using selective 13C labeling and 13C-edited NMR techniques. The three-dimensional structure...

The pseudoknot fold is often seen in auto-catalytic RNA and in viruses. The relative probabilities of different pseudoknot folds predicted by a statistical-mechanical theory is consonant with a database of known folds. We extend that result to estimate the abundance of pseudoknot folds in RNA sequences, finding approximately 1 pseudoknot per 40,000 nucleotides. This theoretical probability dens...

Telomerase is a ribonucleoprotein reverse transcriptase that synthesizes telomeric DNA. A pseudoknot structure is phylogenetically conserved within the RNA component of telomerase in all ciliated protozoans examined. Here, we report that disruptions of the pseudoknot base pairing within the telomerase RNA from Tetrahymena thermophila prevent the stable assembly in vivo of an active telomerase. ...

Telomerase is essential for maintaining telomere length and chromosome stability in stem cells, germline cells, and cancer cells. The telomerase ribonucleoprotein complex consists of two essential components, a catalytic protein component and an RNA molecule that provides the template for telomeric repeat synthesis. A pseudoknot structure in the human telomerase RNA is conserved in all vertebra...

a r t i c l e i n f o a b s t r a c t We study a generalization of the classical notions of bordered and unbordered words, motivated by biomolecular computing. DNA strands can be viewed as finite strings over the alphabet {A, G, C, T}, and are used in biomolecular computing to encode information. Due to the fact that A is Watson–Crick complementary to T and G to C, DNA single strands that are W...

This paper addresses a pseudoknot-freeness problem of DNA and RNA sequences, motivated by biomolecular computing. WatsonCrick (WK) complementarity forces DNA strands to fold into themselves and form so-called secondary structures, which are usually undesirable for biomolecular computational purposes. This paper studies pseudoknot-bordered words, a mathematical formalization of a common secondar...