Methods for the assembly and analysis of in vitro transcription-coupled-to-translation systems

RNA polymerase is a complex machinery, which is further embedded in interactions with other cellular components that interplay with either the transcribed DNA (DNA polymerases, topoisomerases, etc.) or the nascent RNA (RNA processing enzymes, ribosomes, etc.). In prokaryotes, coupling of transcription and translation is thought to play many regulatory roles but the mechanistic understanding of their interactions has been hindered by the lack of a defined experimental system. Here, we describe a pure transcription-coupled-to-translation system in which control of the ribosome has been achieved through its stepwise translocation towards RNA polymerase. This system can be used to study the effects of concurrent translation on RNA chain elongation and to elucidate the interface between the two macromolecular complexes.