The Movement Protein NSm of Tomato Spotted Wilt Tospovirus (TSWV): RNA Binding, Interaction with the TSWV N Protein, and Identification of Interacting Plant Proteins

The nonstructural NSm protein of tomato spotted wilt tospovirus (TSWV) represents a putative viral movement protein involved in cell-to-cell movement of nonenveloped ribonucleocapsid structures. To study the molecular basis of NSm function, we expressed the protein in Escherichia coli and investigated protein-protein and protein-RNA interactions of NSm protein in vitro. NSm specifically interacts with TSWV N protein and binds single-stranded RNA in a sequence-nonspecific manner. Using NSm as a bait in a yeast two-hybrid screen, we identified two homologous NSm-binding proteins of the DnaJ family from Nicotiana tabacum and Arabidopsis thaliana.