The vaccinia virion
is an infectious particle composed of a double-stranded DNA genome surrounded by a capsid, an envelope and adhesion proteins.
The vaccinia virus genome is a linear double-stranded DNA of 186,000 base pairs. It codes for 187 proteins, including structural proteins and non-structural proteins.
The capsid is a protein structure that protects the virus genome. It is made up of 180 capsomeres, which are hexagonal protein units.
The envelope is a lipid membrane that covers the capsid. It contains adhesion proteins that help the virus infect cells.
Adhesion proteins are proteins that bind to receptors on host cells. They help the virus infect cells.
A 3D virtual tour of the vaccinia virion is available on the National Center for Biotechnology Information (NCBI) website. This tour allows users to view the different structures of the virion at different levels of scale.