RNA—PROTEIN CROSSLINK AND RNA CHAIN BREAK FORMATION ON UV-IRRADIATION OF TOBACCO MOSAIC VIRUS

Abstract— The ability of UV-irradiation (254 nm) to induce formation of RNA-protein crosslinks in tobacco mosaic virus (TMV) particles have been studied by Cs₂SO₄ density gradient centrifugation, analytical centrifugation, nitrocellulose filter binding and two-dimensional peptide mapping. RNA-protein crosslinks were found to be formed on UV-irradiation of TMV, but the parallel process of UV-induced RNA chain breakage complicated their quantitation. Using speciall devised equations, the quantum yield of RNA-protein crosslink formation was found to be 0.65 × 10⁻⁵ and that of RNA chain break formation 0.95 × 10⁻⁵.