Coupling between translation and transcription is required for full-length transcripts. The final test of our model for the transcription pattern in our artificial gene fusion was to establish translational coupling beyond the slippery sequence and into the polar termination site (SP) in lacZ. By changing the upstream stop codon between the slippery site and the pseudoknot region into a sense codon ribosomes should, frameshifted or not, follow the RNA polymerase into the beginning of the lacZ sequence.