TOM1, an Arabidopsis gene required for efficient multiplication of a tobamovirus, encodes a putative transmembrane protein

Host-encoded factors play an important role in virus multiplication, acting in concert with virus-encoded factors. However, information regarding the host factors involved in this process is limited, Here we report the map-ba sed cloning of an Arabidopsis thaliana gene, TOM1, which is necessary for t he efficient multiplication of tobamoviruses, positive-strand RNA viruses i nfecting a wide variety of plants, The TOM1 mRNA is suggested to encode a 2 91-aa polypeptide that is predicted to be a multipass transmembrane protein . The Sos recruitment assay supported the hypothesis that TOM1 is associate d with membranes, and in addition, that TOM1 interacts with the helicase do main of tobamovirus-encoded replication proteins, Taken into account that t he tobamovirus replication complex is associated with membranes, we propose that TOM1 participates in the in vivo formation of the replication complex by sewing as a membrane anchor.