Structure of Turnip Yellow Mosaic Virus Crystals in the Electron Microscope

Abstract

IT is known from examination in the electron microscope that turnip yellow mosaic virus¹ consists, in the dry state, of individual particles of spherical form and about 22 mµ in diameter. It readily forms macroscopic crystals, usually octahedra, from aqueous salt solutions. Preliminary X-ray studies indicate that these wet crystals have a large unit cell, and Carlisle suggests² that the lattice may be of the diamond type. Attempts have been made to obtain replicas of the dry crystals, by the method which has proved successful with some other plant viruses^3,4, but these have not shown any regular structure. The failure may be due to the shape of the crystals or to difficulties of drying.