When will the coupled transcription-translation occurs?
Coupled transcription-translation (CTT) occurs when ribosomes bind and start to translate nascent mRNAs, whose transcription has not terminated yet, therefore forming an “RNAP·nascent mRNA·ribosome” complex. Coupling of transcription and translation in prokaryotes.
Coupled transcription-translation (CTT) is a hallmark of prokaryotic gene expression. It occurs when ribosomes bind and start to translate nascent mRNAs, whose transcription has not terminated yet. This allows communication between RNA polymerase, the multisubunit enzyme that catalyzes transcription, and the ribosome, which catalyzes translation.