| RNA polymerase I | <enzyme> A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. The enzyme functions in the nucleolar structure and transcribes DNA into RNA. It has different requirements for cations and salts than RNA polymerase II and III and is not inhibited by alpha-amanitin. Registry number: EC 2.7.7.- (12 Dec 1998) |
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| RNA polymerase II | <enzyme> A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. Registry number: EC 2.7.7.- (12 Dec 1998) |
| RNA polymerase III | <enzyme> A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure where it transcribes DNA into RNA. It has specific requirements for cations and salt and has shown an intermediate sensitivity to alpha-amanitin in comparison to RNA polymerase I and II. Registry number: EC 2.7.7.- (12 Dec 1998) |
| RNA precursors | RNA copies from DNA that exactly represent the genome sequence. This RNA cannot be used for producing protein until RNA splicing takes place. During this procedure the phosphodiester bonds at exon-intron boundaries are cleaved and the intron is excised. Consequently a new bond is formed between the ends of the exons. The resulting RNA is mature RNA which can be translated into protein. (12 Dec 1998) |
| RNA primase | <enzyme, molecular biology> An RNA polymerase that synthesises a short RNA primer sequence to initiate DNA replication. (18 Nov 1997) |
| RNA primer | <molecular biology> The primer sequence synthesised by RNA primase. (23 Aug 1998) |
| RNA probes | RNA, usually prepared by transcription from cloned DNA, which complements a specific mRNA or DNA and is generally used for studies of virus genes, distribution of specific RNA in tissues and cells, integration of viral DNA into genomes, transcription, etc. Whereas DNA probes are preferred for use at a more macroscopic level for detection of the presence of DNA/RNA from specific species or subspecies, RNA probes are preferred for genetic studies. Conventional labels for the RNA probe include radioisotope labels 32p and 125i and the chemical label biotin. RNA probes may be further divided by category into plus-sense RNA probes, minus-sense RNA probes, and antisense RNA probes. (12 Dec 1998) |
| RNA processing | <molecular biology> Modifications of primary RNA trancripts including splicing, cleavage, base modification, capping and the addition of poly A tails. See: RNA editing. (23 Aug 1998) |
| 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. (12 Dec 1998) |
| RNA replicase | <enzyme> An enzyme that catalyses RNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time, and can initiate a chain de novo. (enzyme nomenclature, 1992, p293) Chemical name: Nucleoside-triphosphate:RNA nucleotidyltransferase (RNA-directed) Registry number: EC 2.7.7.48 (12 Dec 1998) |
| RNA splicing | <molecular biology> The removal of introns from primary RNA transcripts. (23 Aug 1998) |
| RNA splicing pattern | <molecular biology> The combination of DNA sequences copied from a gene by messenger RNA. The mRNAs transcribed from a single gene may splice together different parts of the sequence of the gene. (23 Aug 1998) |
| RNA triphosphatase | <enzyme> Removes gamma-phosphate from triphosphate-ended polyribonucleotides Registry number: EC 3.6.1.- (26 Jun 1999) |
| RNA tumour virus | The family of retroviruses (Retroviridae) that can cause tumours. They are enveloped by membrane derived from the plasma membrane of the host cell, from which they are released by budding without lysing the cell. Within each virion is a pair of single stranded RNA molecules. Replication involves a DNA intermediate made on an RNA template by the enzyme reverse transcriptase. (18 Nov 1997) |
| RNA tumour viruses | Virus's of the subfamily Oncovirinae. (05 Mar 2000) |
| polymerase, RNA | Enzyme that catalyses (speeds) the polymerization of RNA. Rna polymerase uses preexisting nucleic acid templates and assembles the RNA from ribonucleotides. (12 Dec 1998) |
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| positive strand RNA viruses | Class IV and VI viruses that have a single stranded RNA genome that can act as mRNA plus strand) and in which the virus RNA is itself infectious. Includes Picornaviridae, Togaviridae and Retroviridae. (18 Nov 1997) |
| CTP-RNA cytidylyltransferase | <enzyme> Catalyses addition of cmp residue to 3'-ends of oligonucleotide primers Registry number: EC 2.7.7.- Synonym: terminal cytidylyltransferase (26 Jun 1999) |
| pre-ribosomal RNA endoribonuclease | <enzyme> Substrate is pre-rrna Registry number: EC 3.1.26.- Synonym: pre-rrna endoribonuclease (26 Jun 1999) |
| prolyl T RNA synthetase | <enzyme> Minor descriptor (75-84); on-line and index medicus search amino acyl t RNA synthetases (75-84) Registry number: EC 6.1.1.15 Synonym: l-proline-trna-pro ligase (AMP-forming) (26 Jun 1999) |
| satellite RNA | <molecular biology> A small, self-splicing RNA molecule that accompanies several plant viruses, including tobaccoringspot virus. (09 Oct 1997) |
| heterogeneous nuclear RNA | An ill-defined form of RNA, of high molecular weight, that never leaves the nucleus and is thought to be the precursor of messenger RNA. (05 Mar 2000) |
| heterogenous nuclear RNA | <molecular biology> Originally identified as a class of RNA, found in the nucleus but not the nucleolus, which is rapidly labelled and with a very wide range of sizes, 2-40 kilobases. It represents the primary transcripts of RNA polymerase II and includes precursors of all messenger RNAs from which introns are removed by splicing. (18 Nov 1997) |
| sequence analysis, RNA | A multistage process that includes RNA cloning, physical mapping, subcloning, sequencing, and information analysis. (12 Dec 1998) |
| sisomicin-gentamicin resistance ribosomal RNA methylase | <enzyme> Catalyses the methylation of 30s ribosomal units to confer sisomicin-gentamicin resistance in micromonospora zionensis Registry number: EC 2.1.1.- Synonym: sgm gene product, sgm methylase (26 Jun 1999) |
| small nuclear 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) |
| soluble RNA | rNA |
| negative stranded RNA virus | <virology> Class V viruses that have an RNA genome that is complementary to the mRNA, the positive strand. They also carry the virus specific RNA polymerase necessary for the synthesis of the mRNA. Includes (Rhabdoviridae, Paramyxoviridae and Myoviridae (for example the T even phages). (18 Nov 1997) |
| nuclear RNA | <molecular biology> The nucleus contains RNA that has just been synthesised, but in addition there is some that seems not to be released or is only released after further processing, the heterogenous nuclear RNA (hnRNA) and small RNA molecules associated with protein to form small nuclear ribonucleoproteins. (18 Nov 1997) |
| DNA-directed RNA polymerase | <enzyme> A group of enzymes that catalyses DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesised. Chemical name: Nucleoside-triphosphate:RNA nucleotidyltransferase (DNA-directed) Registry number: EC 2.7.7.6 (12 Dec 1998) |