STUDIES ON THE INACTIVATION OF TOBACCO MOSAIC VIRUS BY ULTRAVIOLET LIGHT*,‡,§

Abstract— The irradiation of TMV with u.v. light of 2537 Å wavelength results in the binding of protein subunits to the RNA. These bound subunits are stable towards warm sodium dodecyl-sulfate; however, the binding is not covalent since the subunits are removed by 66% acetic acid, guanidine hydrochloride, or phenol. Approximately one protein subunit is bound per lethal biological ‘hit’. The virus and the nucleic acid extracted from irradiated virus show virtually identical rates of inactivation.