Localization of a single-stranded RNA-binding domain in the movement protein of red clover necrotic mosaic dianthovirus

Mutant movement proteins of red clover necrotic mosaic dianthovirus (RCNMV), consisting of in-frame deletions or fusions with a maltose-binding protein, were pro-duced in Escherichia coli using expression vectors. The ability of the mutant proteins to bind to ssRNA was tested by photochemical cross-linking and gel retar-dation. The results showed that the region between amino acids 181 and 225 of the RCNMV movement protein contains an ssRNA-binding domain. There is a growing body of evidence that movement of plant viruses from cell to cell occurs via the intercellular channels known as plasmodesmata, and is mediated by virus-encoded movement proteins (for review, see Hull