Читать книгу Chemistry and Biology of Non-canonical Nucleic Acids - Naoki Sugimoto - Страница 40

Pseudoknot is one of the intramolecular tertiary structure motifs characterized by base pairing between the single-stranded regions in a hairpin such as loop and bulge with a region outside of the hairpin (Figure 2.17) [35]. Based on this definition, irrespective of the distance of nucleobases, it can be regarded as a pseudoknot when a region that is in the middle of the region forming particular stem contributes to the formation of another stem with another RNA region. When long RNA strands such as rRNA and internal ribosome entry site (IRES) form specific structures, pseudoknots are often formed in distant regions. Since the biological functions of pseudoknot are well studied during translation, the detailed structures and their contributions are described in Chapter 7.