THE FORMATION OF PHOTOREVERSIBLE CYCLOBUTANE-TYPE PYRAMIDING DIMERS IN ULTRAVIOLET POTATO VIRUS

摘要

Photoreversible cyclobutaenc-type pyrimidine dimmers were found in 32P-labeled NRA isolated from intact potate virus X irradiated with 254 nm light. The number of dimmers was correlated with the biological infectivity of the ultraviolet-treated virus. Assuming that incorported 32P is homogenesualy distributed in the viral RNA chain, it can be calculated that about 5.7±1.7 dimers are present in each strand of virus per lethal biological hit.