| Rn | Symbol for radon. (05 Mar 2000) |
|---|---|
| RNA | <molecular biology> A nucleic acid found in all living cells. Plays a role in transferring information from DNA to the protein-forming system of the cell. (16 Dec 1997) |
| RNA 2'-O-methyltransferase | <enzyme> Methylates 2'-hydroxyl group of ribose moieties of ribosomal RNA; highest activity poly (c) is a synthetic substrate Registry number: EC 2.1.1.- Synonym: nucleolar 2'-o-methyltransferase (26 Jun 1999) |
| RNA 3'-terminal phosphate cyclase | <enzyme> ATP dependent; forms 2',3' terminal cyclic phosphate on RNA which is then the substrate for RNA ligase of hela cells Registry number: EC 6.5.- Synonym: RNA tph cyclase (26 Jun 1999) |
| RNA cap analogs | Analogs of RNA cap compounds which do not have a positive charge. These compounds inhibit the initiation of translation of both capped and uncapped messenger RNA. (12 Dec 1998) |
| RNA caps | Compounds with the general structure 7-methyl-5'-guanosine triphosphate-5'-x which modify the 5' end of eukaryotic cellular and viral messenger RNA and some heterogeneous nuclear rnas. These compounds, which are positively charged, protect the above specified rnas at their termini against attack by phosphatases and other nucleases and promote mRNA function at the level of initiation of translation. Analogs of the RNA caps (RNA cap analogs), which lack the positive charge, inhibit the initiation of protein synthesis. (12 Dec 1998) |
| RNA editing | <molecular biology> Specific alterations of RNAs, for example C_V changes that are not coded for in the genes. (23 Aug 1998) |
| RNA enzyme | <molecular biology> Often referred to as RNA with catalytic capacity, an enzyme made of nucleic acid not protein that catalyse chemical reactions, often the breakdown of other RNAs. Of particular interest because of the implications for self replicating systems in the earliest stages of the evolution of (terrestrial) life. Their discovery in the mid-1980s refuted the concept that only proteins could be biological catalysts. There is potential for their use as pharmaceuticals and industrial catalysts. (13 Nov 1997) |
| RNA helicase | <enzyme> Nuclear envelope-associated RNA helicase activity in nucleocytoplasmic RNA transport; both glh-1 and glh-2 contain cchc-type zinc fingers; xp54 is xenopus homologue of human RNA helicase p54 Registry number: EC 2.7.7.- Synonym: RNA duplex unwindase, p54 gene product, bat1 gene product, RNA helicase a, rok1 protein, human RNA helicase 1, hrh1 protein, mrdb protein, glh-1 protein, glh-2 protein, RNA helicase p54, xp54, u5 snrnp-specific 100-kD protein (26 Jun 1999) |
| RNA life | <biology, molecular biology> A hypothetical life form lacking DNA and protein which may have existed on early earth and in which RNA served both a genetic coding and a catalytic function. (23 Aug 1998) |
| RNA ligase | <enzyme> An enzyme that catalyses the conversion of linear RNA to a circular form by the transfer of the 5'-phosphate to the 3'-hydroxyl terminus. It also catalyses the covalent joining of two polyribonucleotides in phosphodiester linkage. Chemical name: Poly(ribonucleotide):poly(ribonucleotide)ligase (AMP-forming) Registry number: EC 6.5.1.3 (12 Dec 1998) |
| RNA N-glycosidase | <enzyme> Catalyses hydrolysis of a single adenosine glycosidic bond; probable cause of toxic effect of vero toxin from E coli by inactivating 60s ribosomal subunit Registry number: EC 3.2.2.- Synonym: RNA glycosylase (26 Jun 1999) |
| RNA nucleotidyltransferases | <enzyme> Enzymes that catalyze the template-directed incorporation of ribonucleotides into an RNA chain. Registry number: EC 2.7.7. (12 Dec 1998) |
| RNA phages | Bacteriophages whose genetic material is RNA, which is single-stranded in all except the pseudomonas phage phi6. All RNA phages infect their host bacteria via the host's surface pili. Some frequently encountered RNA phages are: qbeta, ms2, bf23, f2, r17, fr, mu2, phicb5, phicb12r, phicb8r, phicb23r, 7s, phi6, pp7. (12 Dec 1998) |
| RNA plasmid | <molecular biology> DsRNA found in yeasts, also called killer factors. Their nomenclature is uncertain and some scientists consider them viruses. (23 Aug 1998) |