National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
米国
引用
ジャーナル: Nature / 年: 2023 タイトル: Structural basis of Rho-dependent transcription termination. 著者: Vadim Molodtsov / Chengyuan Wang / Emre Firlar / Jason T Kaelber / Richard H Ebright / 要旨: 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- ...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. 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.