RT Journal Article SR Electronic T1 Escherichia coli NusG links the lead ribosome with the transcription elongation complex JF bioRxiv FD Cold Spring Harbor Laboratory SP 871962 DO 10.1101/871962 A1 Robert S. Washburn A1 Philipp K. Zuber A1 Ming Sun A1 Yaser Hashem A1 Bingxin Shen A1 Wen Li A1 Sho Harvey A1 Stefan H. Knauer A1 Joachim Frank A1 Max E. Gottesman YR 2019 UL http://biorxiv.org/content/early/2019/12/11/871962.abstract AB It has been known for more than 50 years that transcription and translation are physically coupled in bacteria, but whether or not this coupling may be mediated by the two-domain protein N-utilization substance (Nus) G in Escherichia coli is still heavily debated. Here, we combine integrative structural biology and functional analyses to provide conclusive evidence that NusG can physically link transcription with translation by contacting both RNA polymerase and the ribosome. We present a cryo-electron microscopy structure of a NusG:70S ribosome complex and nuclear magnetic resonance spectroscopy data revealing simultaneous binding of NusG to RNAP and the intact 70S ribosome, providing the first direct structural evidence for NusG-mediated coupling. Furthermore, in vivo reporter assays show that recruitment of NusG occurs late in transcription and strongly depends on translation. Thus, our data suggest that coupling occurs initially via direct RNAP:ribosome contacts and is then mediated by NusG.