Biomaterial Database

Self-cleaving viroid and newt RNAs may only be active as dimers. 1988

A C Forster, and C Davies, and C C Sheldon, and A C Jeffries, and R H Symons

Department of Biochemistry, University of Adelaide, South Australia.

Avocado sunblotch viroid (ASBV) is a 247-nucleotide, single-stranded, circular RNA. It is considered to replicate via a rolling-circle mechanism in which circular, monomeric plus and minus RNAs act as templates for the synthesis of longer-than-unit-length precursor RNAs. Processing of these RNAs in vivo may occur by a self-cleavage reaction, as indicated by ability of dimeric, linear plus and minus ASBV RNAs to specifically self-cleave in vitro with the excision of a monomeric RNA with 5'-hydroxyl and 2',3'-cyclic phosphodiester termini. A similar self-cleavage reaction has also been reported to occur in an RNA transcript containing a dimeric copy of a tandemly repeated, 330-base-pair sequence of the newt genome. Based on comparisons with self-cleaving plant viral satellite RNAs, hammerhead-shaped active structures, each containing one self-cleavage site, were proposed for the plus and minus ASBV RNAs and the newt RNA, but the stability of these hammerheads has been questioned. Here, more stable active structures that contain two self-cleavage sites are proposed and data supporting these models are presented.

UI	MeSH Term	Description	Entries
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D004252	DNA Mutational Analysis	Biochemical identification of mutational changes in a nucleotide sequence.	Mutational Analysis, DNA,Analysis, DNA Mutational,Analyses, DNA Mutational,DNA Mutational Analyses,Mutational Analyses, DNA
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012313	RNA	A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	RNA, Non-Polyadenylated,Ribonucleic Acid,Gene Products, RNA,Non-Polyadenylated RNA,Acid, Ribonucleic,Non Polyadenylated RNA,RNA Gene Products,RNA, Non Polyadenylated
D012323	RNA Processing, Post-Transcriptional	Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.	Post-Transcriptional RNA Modification,RNA Processing,Post-Transcriptional RNA Processing,Posttranscriptional RNA Processing,RNA Processing, Post Transcriptional,RNA Processing, Posttranscriptional,Modification, Post-Transcriptional RNA,Modifications, Post-Transcriptional RNA,Post Transcriptional RNA Modification,Post Transcriptional RNA Processing,Post-Transcriptional RNA Modifications,Processing, Posttranscriptional RNA,Processing, RNA,RNA Modification, Post-Transcriptional,RNA Modifications, Post-Transcriptional
D012330	RNA, Double-Stranded	RNA consisting of two strands as opposed to the more prevalent single-stranded RNA. Most of the double-stranded segments are formed from transcription of DNA by intramolecular base-pairing of inverted complementary sequences separated by a single-stranded loop. Some double-stranded segments of RNA are normal in all organisms.	Double-Stranded RNA,Double Stranded RNA,RNA, Double Stranded
D012367	RNA, Viral	Ribonucleic acid that makes up the genetic material of viruses.	Viral RNA
D012455	Salamandridae	A family of Urodela consisting of 15 living genera and about 42 species and occurring in North America, Europe, Asia, and North Africa.	Newts,Taricha,Newt,Tarichas