1985 Articles

Two Integrated Partial Repeats of Simian Virus 40 Together Code for a Super-T Antigen

Levitt, Alexandra; Chen, Suzie; Blanck, George; George, Diane; Pollack, Robert

We determined that the coding sequence for a 100-kilodalton super-T antigen found in Simian virus 40 mouse transformants spanned two separate partial repeats of the viral genome. The downstream repeat contained a complete Simian virus 40 large-T-antigen gene, whereas the upstream repeat was a truncated copy of the same gene. When the repeats were separated by subcloning, the capacity to code for the super-T antigen was lost. A small insertion or deletion in the origin-control region which preceded the second repeat could also destroy the ability to code for the 100-kilodalton protein. Our data suggest that differential splicing between parts of two gene copies was responsible for the additional molecular weight of this supekr-T antigen.