Structure of dahlemense strain of tobacco mosaic virus: A periodically deformed helix

X-ray diffraction photographs from dahlemense strain of tobacco mosaic virus show that it is very similar to the common strain, but additional meridional and near-meridional diffraction maxima appear on layer lines halfway between those given by the common strain. These are interpreted as arising from a regular perturbation of the arrangement of the outer part of the protein subunit. A theoretical discussion of the effects of a periodic...