Sense RNA virus

Sense RNA virus

Virology, the genome of an RNA virus can be seen as either positive-sense, also known as "plus - strand” or negative direction , also known as a " minus strand " .

Whether a virus genome is of positive or negative direction can be used as a basis for classification of virus.

Positive direction

Positive direction (5 'to 3’) of the viral RNA, a sequence of particular means viral RNA can be directly translated into viral proteins desired.

Therefore, in the virus RNA of positive sense, the genome of the viral RNA can be considered the viral mRNA, and can be immediately translated by the host cell.

Unlike negative-sense RNA, positive-sense RNA is of the same sense as mRNA.

Some viruses (e.g. , Coronaviridae ) positive direction have genomes that can play the role of the mRNA and be directly used to synthesize the protein without using a complementary RNA intermediate .

Therefore, these viruses do not need to have an RNA polymerase packaged into the virion .

Negative direction

Negative-sense (3 'to 5’) of the viral RNA is complementary to the viral mRNA, and therefore it a positive sense RNA must be produced by a polymerase RNA before translation.

The negative-sense RNA (such as DNA) has a nucleotide sequence complementary to the mRNA that encodes it.

Like DNA, RNA that cannot be directly translated into protein .

Instead, it must first be transcribed into a positive-sense RNA acts as an mRNA.

Some viruses (influenza, for example ) have negative sense genome and therefore must carry an RNA polymerase within the virion .