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Negative-strand RNA viruses (−ssRNA viruses) are a group of related viruses that have negative-sense, single-stranded genomes made of ribonucleic acid (RNA). They have genomes that act as complementary strands from which messenger RNA (mRNA) is synthesized by the viral enzyme RNA-dependent RNA polymerase (RdRp). During replication of the ...
Viruses of the family Orthomyxoviridae contain six to eight segments of linear negative-sense single stranded RNA. They have a total genome length that is 10,000–14,600 nucleotides (nt). [ 7 ] The influenza A genome , for instance, has eight pieces of segmented negative-sense RNA (13.5 kilobases total).
Riboviria contains three types of viruses that replicate via RdRp: single-stranded RNA (ssRNA) viruses, which are either positive (+) or negative (-) sense, and double-stranded RNA viruses (dsRNA), all of which belong to the kingdom Orthornavirae. +ssRNA viruses have genomes that can functionally act as mRNA, and a negative-sense strand can ...
In contrast, purified RNA of a negative-sense virus is not infectious by itself as it needs to be transcribed into positive-sense RNA; each virion can be transcribed to several positive-sense RNAs. Ambisense RNA viruses resemble negative-sense RNA viruses, except they translate genes from their negative and positive strands. [6]
Since RNA-dependent RNA polymerase does not have an error-checking function, many mutations are made when the RNA is processed. These mutations build up and eventually new strains are created. Due to this concept, one would expect that paramyxoviruses should not be antigenically stable; however, the opposite is seen to be true.
Negative-sense (3′-to-5′) viral RNA is complementary to the viral mRNA, thus a positive-sense RNA must be produced by an RNA-dependent RNA polymerase from it prior to translation. Like DNA, negative-sense RNA has a nucleotide sequence complementary to the mRNA that it encodes; also like DNA, this RNA cannot be translated into protein directly.
Viruses containing nonsegmented genomes for which the first step in replication is transcription from the negative-stranded genome by the viral RNA-dependent RNA polymerase to yield monocistronic mRNAs that code for the various viral proteins. A positive-sense genome copy that serves as template for production of the negative-strand genome is ...
Transcription of mRNAs initiated by viral polymerase using cap snatching. The first step of transcription for some negative, single-stranded RNA viruses is cap snatching, in which the first 10 to 20 residues of a host cell RNA are removed (snatched) and used as the 5′ cap and primer to initiate the synthesis of the nascent viral mRNA. [1]