Cripavirus

Cripaviruses are a genus of + sense, single-stranded RNA (ssRNA) viruses. It can produce proteins directly from their RNA genome upon entering a cell; and therefore, does not require an RNA polymerase packaged in with it, as this may be produced from the genome after entering the cell.^[1]

The genome is 8500–9500 nucleotides long, and has a VPg (genome linked viral protein) on the 5' end. The 5' end also has a series of C's near it, while the 3' end has a series of A's near it.

These viruses have capsids of 12 capsomers but no envelope, and are round 27–30 nm in diameter with an icosahedral symmetry.

The name of the cripavirus family originates from its most famous member the Cricket Paralysis Virus.^[1] Which was made famous by its rather unique IRES (Internal Ribosome Entry Site): the Cripavirus IRES. The Cripavirus IRES is an RNA element that allows the virus to bind the ribosome and translate without a need for any initiation factors^[2] – as initiation is the most regulated step of translation this allows the virus to avoid many mechanisms to inhibit viral activity.

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