The REB1 site is an essential component of a terminator for RNA polymerase I in Saccharomyces cerevisiae.

We have identified a terminator for transcription by RNA polymerase I in the genes coding for rRNA of the yeast Saccharomyces cerevisiae. The terminator is located 108 bp downstream of the 3' end of the mature 25S rRNA and shares several characteristics with previously studied polymerase I terminators in the vertebrates. For example, the yeast terminator is orientation dependent, is inhibited by its own sequence, and forms RNA 3' ends 17 +/- 2 bp upstream of an essential protein binding site. The recognition sequence for binding of the previously cloned REB1 protein (Q. Ju, B. E. Morrow, and J. R. Warner, Mol. Cell. Biol. 10:5226-5234, 1990) is an essential component of the terminator. In addition, the efficiency of termination depends upon sequence context extending at least 12 bp upstream of the REB1 site.