The hand of the stacked-disk aggregate of tobacco mosaic virus protein

The hand of the helical arrangement of subunits in the stacked-disk form of tobacco mosaic virus protein has been determined from electron microscopy. This and previous structural results taken together indicate that the near-axial intersubunit contacts between disks are similar to those within a single disk but quite different from those in the virus. Discrepancies between the structures of single disks and stacked disks are attributed to cleavage of the protein within the stacked-disk rod.