Structural basis of Rho-dependent transcription termination.
Molodtsov, V., Wang, C., Firlar, E., Kaelber, J.T., Ebright, R.H.(2023) Nature 614: 367-374
- PubMed: 36697824 
- DOI: https://doi.org/10.1038/s41586-022-05658-1
- Primary Citation of Related Structures:  
8E3F, 8E3H, 8E5K, 8E5L, 8E5O, 8E5P, 8E6W, 8E6X, 8E6Z, 8E70 - PubMed Abstract: 
Rho is a ring-shaped hexameric ATP-dependent molecular motor. Together with the transcription elongation factor NusG, Rho mediates factor-dependent transcription termination and transcription-translation-coupling quality control in Escherichia coli 1-4 . Here we report the preparation of complexes that are functional in factor-dependent transcription termination from Rho, NusG, RNA polymerase (RNAP), and synthetic nucleic acid scaffolds, and we report cryogenic electron microscopy structures of the complexes. The structures show that functional factor-dependent pre-termination complexes contain a closed-ring Rho hexamer; have RNA threaded through the central channel of Rho; have 60 nucleotides of RNA interacting sequence-specifically with the exterior of Rho and 6 nucleotides of RNA interacting sequence-specifically with the central channel of Rho; have Rho oriented relative to RNAP such that ATP-dependent translocation by Rho exerts mechanical force on RNAP; and have NusG bridging Rho and RNAP. The results explain five decades of research on Rho and provide a foundation for understanding Rho's function.
Organizational Affiliation: 
Waksman Institute and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, USA.