Only one of two closely related yeast suppressor tRNA genes contains an intervening sequence

Abstract
The yeast genes that code for the serine-inserting SUP-RL1 amber and SUQ5 ochre suppressors were cloned and sequenced. These 2 unlinked genes differ by only 3 base pairs in their coding regions yet they encode tRNA of different translational specificities, and while the SUP-RL1 gene has a 19-base pair intervening sequence, the SUQ5 gene has none.