Contributes to the intracellular multiplication of tobamoviruses, probably being a membrane anchor promoting the formation of the replication complex. Constituent of tobamovirus replication complex. When associated with TOM1 disruption, reduced efficiency of intracellular multiplication of tobamoviruses (e.g. crucifer strain TMV-Cg), characterized by a reduced accumulation of viral coat protein (CP) and reduced amplification of TMV-related RNAs. Belongs to the plant tobamovirus multiplication TOM1 protein family. Extended N-terminus. Truncated N-terminus.