Negative polarity

Definition

Negative polarity refers to the orientation of viral RNA genomes that are complementary to the viral mRNA. This means they must be transcribed by an RNA polymerase into a positive-sense RNA before translation can occur.

5 Must Know Facts For Your Next Test

1. Negative polarity RNA viruses require RNA-dependent RNA polymerase for replication.
2. Examples of negative-sense RNA viruses include Influenza, Rabies, and Ebola.
3. Negative polarity genomes cannot directly code for proteins and need to be converted to positive sense.
4. The negative strand serves as a template for producing multiple copies of positive-sense RNA.
5. Viruses with negative polarity typically package their own RNA polymerase enzyme within their virions.

Review Questions

Related terms

Positive Polarity: Positive polarity refers to viral RNA genomes that can directly serve as mRNA for protein synthesis.

RNA-dependent RNA Polymerase: An enzyme used by some viruses to replicate their RNA genomes.

Virion: The complete, infectious form of a virus outside a host cell, with its genome enclosed in a protein coat.