| 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) |
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| RNA, ribosomal | A component of ribosomes, ribosomal RNA functions as a non-specific site for making polypeptides. Ribosomal RNA is abbreviated rrna. (12 Dec 1998) |
| RNA, ribosomal, 16s | Constituent of 30s subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16s rrna is involved in initiation of polypeptide synthesis. (12 Dec 1998) |
| RNA, ribosomal, 18s | Constituent of the 40s subunit of eukaryotic ribosomes. 18s rrna is involved in the initiation of polypeptide synthesis in eukaryotes. (12 Dec 1998) |
| RNA, ribosomal, 23s | Constituent of 50s subunit of prokaryotic ribosomes containing about 3200 nucleotides. 23s rrna is involved in the initiation of polypeptide synthesis. (12 Dec 1998) |
| RNA, ribosomal, 28s | Constituent of the 60s subunit of eukaryotic ribosomes. 28s rrna is involved in the initiation of polypeptide synthesis in eukaryotes. (12 Dec 1998) |
| RNA, ribosomal, 5.8s | Constituent of the 60s subunit of eukaryotic ribosomes. 5.8s rrna is involved in the initiation of polypeptide synthesis in eukaryotes. (12 Dec 1998) |
| RNA, ribosomal, 5s | Constituent of the 50s subunit of prokaryotic ribosomes containing about 120 nucleotides and 34 proteins. It is also a constituent of the 60s subunit of eukaryotic ribosomes. 5s rrna is involved in initiation of polypeptide synthesis. (12 Dec 1998) |
| RNA, satellite | Small, linear single-stranded RNA molecules functionally acting as molecular parasites of certain RNA plant viruses. Satellite rnas exhibit four characteristic traits: 1) they require helper viruses to replicate; 2) they are unnecessary for the replication of helper viruses; 3) they are encapsidated in the coat protein of the helper virus; 4) they have no extensive sequence homology to the helper virus. Thus they differ from satellite viruses which encode their own coat protein, and from the genomic RNA (=RNA, viral) of satellite viruses. (12 Dec 1998) |
| RNA, small nuclear | Short chains of RNA found in the nucleus. Their function is to remove the introns (nontranslated intervening sequences) from mRNA precursors, thereby bringing the two exons (coding segments) together into correct juxtaposition for enzymatic splicing at the correct point. The resulting mRNA is now ready to leave the nucleus. (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) |