RNA viruses

RNA viruses,

n See viruses.

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RNA

ribonucleic acid.

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RNA interference (RNAi)

the functional inactivation of specific genes by experimental introduction of a corresponding double stranded RNA, which induces degradation of the complementary single-stranded mRNA encoded by the gene but not that of mRNAs with different sequences. See microRNA and gene silencing.

microRNA (miRNA)

small RNAs containing 21 to 33 nucleotides that associated with multiple proteins in a RNA-induced silencing complex (RISC) that repress transcription of specific target mRNA by hybridizing to its 3' untranslated region.

RNA primer

a sequence of about 10 nucleotides long copied from DNA by RNA primase and required for the priming of the synthesis of each Okazaki fragment during DNA replication.

secondary structure RNA

folding of single-stranded RNA molecules which arises from intramolecular base pairing.

small cytoplasmic RNA (scRNA)

small (7S; 129 nucleotides) RNA molecules found in the cytosol and rough endoplasmic reticulum associated with proteins that are involved in specific selection and transport of other proteins.

small nuclear RNA (snRNA)

a general term for many diferent kinds of small RNA molecules found in the nucleus of a cell that include as examples species involved in splicing of introns from mRNA and in RNA interference.

RNA viruses

viruses distinguished by having a ribonucleic acid genome, usually as a single strand which may be positive or negative sense, a single molecule or a segmented; in at least two families the genome is a double-strand segmented form.