Transcription terminates in yeast distal to a control sequence.

We have investigated transcription termination on a segment of Drosophila DNA that complements a yeast adenine-8 mutation. Poly(A)+ RNA transcribed from this segment in yeast terminates at multiple sites clustered just beyond an AAUAAA sequence implicated in polyadenylation of higher eucaryotic messages. Deletion analysis indicates that, in yeast, this sequence is not required for polyadenylation. Rather, transcription termination is signalled by a region that is upstream of the AAUAAA sequence. At least part of the control region appears to be an 8-base pair (bp) sequence also found in the termination control region of the yeast CYC1 gene. Termination sites for the various deletions show a clear sequence preference. These sites occur in clusters at least 50 bp downstream of the control region, suggesting similarities between termination in yeast and p-dependent termination in bacteria.