To replicate, a virusoid depends on a helper virus, which is typically a member of the Sobemovirus family, such as the subterranean clover mottle virus. The virusoid is packaged inside the helper virus's capsid and is released into the host cell's cytoplasm upon entry. In the cytoplasm, the virusoid exhibits ribozyme activity to facilitate its replication, while the helper virus replicates independently of the virusoid.