3' processing in Dictyostelium: unusual sequence requirements and interaction with a downstream promoter

We have determined the sequence requirements for 3'-processing in Dictyostelium and find that a single AATAAA site, embedded in an A/T-rich environment is sufficient. A synthetic oligonucleotide containing the additional GT/T-rich element, which is necessary for 3'-processing in higher eukaryotes, is not used in Dictyostelium. On the basis of reports suggesting termination signals (upstream terminators) in Dictyostelium promoters, we investigated possible interactions between processing signals and regulatory elements. Our data suggest that upstream termination enhances transcription from a downstream promoter.