Domain interactions of the transcription:translation coupling factor E. coli NusG are intermolecular and transient.

Bjoern Burmann , Ulrich Scheckenhofer , Kristian Schweimer , Paul Rösch (1)

1 Biopolymere

The bacterial transcription factor NusG is suggested to act as a key coupling factor between transcription and translation (Burmann et al. 2010 Science. 328:501-504). and contributes to phage λ mediated antitermination in E. coli that enables read-through of early transcription termination sites. E. coli NusG consists of two structurally and functionally distinct domains that are connected via a flexible linker. The homologous Aquifex aeolicus NusG with a secondary structure that is highly similar to E. coli NusG shows direct interaction between its N-terminal and its C-terminal domain in a domain-swapped dimer. Here we performed NMR paramagnetic relaxation enhancement measurements and identified interdomain interactions that were concentration dependent and thus likely not only weak and transient, but also predominantly intermolecular. This notion of two virtually independent domains in a monomeric protein was supported by 15N relaxation measurements. Thus, we suggest a regulatory role of NusG interdomain interactions to be highly unlikely.

Mots clés: Life Sciences

Bjoern Burmann, Ulrich Scheckenhofer, Kristian Schweimer, Paul Rösch. Domain interactions of the transcription:translation coupling factor E. coli NusG are intermolecular and transient.. Biochemical Journal, 2011, 435 (3), pp.783-789. ⟨10.1042/BJ20101679⟩. ⟨hal-00586465⟩