A widely conserved protein Rof inhibits transcription termination factor Rho and promotes Salmonella virulence program

• Published in: Nature communications 2024-04, Vol.15 (1), p.3187-3187, Article 3187
• Main Authors: Zhang, Jing, Zhang, Shuo, Zhou, Wei, Zhang, Xiang, Li, Guanjin, Li, Ruoxuan, Lin, Xingyu, Chen, Ziying, Liu, Fang, Shen, Pan, Zhou, Xiaogen, Gao, Yue, Chen, Zhenguo, Chao, Yanjie, Wang, Chengyuan
• Format: Article
• Language: English
• Subjects: 101/28; 631/326/41/2532; 631/45/535/1258/1259; 82/83; Bacteria; Bacteria - genetics; Binding sites; Changing environments; Electron microscopy; Environmental changes; Gene expression; Gene Expression Regulation, Bacterial; Humanities and Social Sciences; multidisciplinary; Pathogenesis; Proteins; Rho Factor - genetics; Rho Factor - metabolism; Salmonella; Salmonella typhimurium - genetics; Salmonella typhimurium - metabolism; Science; Science (multidisciplinary); Transcription Factors - metabolism; Transcription termination; Transcription termination factor RHO; Transcription, Genetic; Virulence; Virulence - genetics
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-47438-7

Transcription is crucial for the expression of genetic information and its efficient and accurate termination is required for all living organisms. Rho-dependent termination could rapidly terminate unwanted premature RNAs and play important roles in bacterial adaptation to changing environments. Although Rho has been discovered for about five decades, the regulation mechanisms of Rho-dependent termination are still not fully elucidated. Here we report that Rof is a conserved antiterminator and determine the cryogenic electron microscopy structure of Rho-Rof antitermination complex. Rof binds to the open-ring Rho hexamer and inhibits the initiation of Rho-dependent termination. Rof’s N-terminal α-helix undergoes conformational changes upon binding with Rho, and is key in facilitating Rof-Rho interactions. Rof binds to Rho’s primary binding site (PBS) and excludes Rho from binding with PBS ligand RNA at the initiation step. Further in vivo analyses in Salmonella Typhimurium show that Rof is required for virulence gene expression and host cell invasion, unveiling a physiological function of Rof and transcription termination in bacterial pathogenesis. Bacterial protein Rof (Rho-off) directly interacts with bacterial factor Rho and inhibits Rho-dependent transcription termination. Here, authors report cryo-EM structure of Rho-Rof antitermination complex and reveal their role in bacterial pathogenesis.