IS10 ANTISENSE CONTROL IN-VIVO IS AFFECTED BY MUTATIONS THROUGHOUT THE REGION OF COMPLEMENTARITY BETWEEN THE INTERACTING RNAS

Translation of the IS10 transposase mRNA (RNA-IN) is inhibited by anti sense pairing with a small IS10 encoded transcript called RNA-OUT. To further characterize IS10 antisense control, an extensive set of mutat ions in the region of complementarity between RNA-OUT, and its target RNA-IN have been isolated. These mutations have been characterized for their effects on antisense inhibition of transposase gene translation in vivo. Mutations that confer the strongest defects on translational inhibition are found in the region corresponding to the 5' end of RNA -IN. However, mutations throughout the complementary region affect ant isense control regardless of whether mutations are present in RNA-IN a lone or as complementary mutations in both RNAs. An analysis of the da ta presented here suggests that in vivo pairing rates for the wild-typ e antisense species are very close to being optimal. Some of the motif s found in antisense molecules that may be associated with efficient p airing rates are discussed.