TY - JOUR T1 - Nus factors have a widespread regulatory function in bacteria JF - bioRxiv DO - 10.1101/091223 SP - 091223 AU - Gabriele Baniulyte AU - Navjot Singh AU - Courtney Benoit AU - Richard Johnson AU - Robert Ferguson AU - Mauricio Paramo AU - Anne M. Stringer AU - Ashley Scott AU - Pascal Lapierre AU - Joseph T. Wade Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/12/02/091223.abstract N2 - Nus factors are broadly conserved across bacterial species, and are often essential for viability. A complex of five Nus factors (NusB, NusE, NusA, NusG and SuhB) is considered to be a dedicated regulator of ribosomal RNA folding, and has been shown to prevent Rho-dependent transcription termination. We have established the first cellular function for the Nus factor complex beyond regulation of ribosomal assembly: repression of the Nus factor-encoding gene, suhB. This repression occurs by translation inhibition followed by Rho-dependent transcription termination. Thus, Nus factors can prevent or promote Rho activity depending on the gene context. Extensive conservation of NusB/E binding sites upstream of nus factor genes indicates that Nus factor autoregulation likely occurs in many species. Putative NusB/E binding sites are also found upstream of many other genes in diverse species, and we demonstrate Nus factor regulation of one such gene in Citrobacter koseri. We conclude that Nus factors have an evolutionarily widespread regulatory function beyond ribosomal RNA, and that they are often autoregulatory. ER -