Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
A helical virus is a type of virus whose capsid (protein shell) is shaped in a rod-like, spiral structure. This shape allows the viral nucleic acid to be tightly wound inside the protein coat.
5 Must Know Facts For Your Next Test
Helical viruses can infect both plants and animals.
The Tobacco Mosaic Virus (TMV) is a well-known example of a helical virus.
These viruses have a single-stranded RNA or DNA genome.
The capsid proteins of helical viruses self-assemble into a helical structure around the nucleic acid.
They often exhibit symmetry, with the length of the helix determined by the length of the nucleic acid.