Identification of a conserved branched RNA structure that functions as a factor-independent terminator
Author(s)Johnson, Christopher M.; Yuqing, Chen; Lee, Heejin; Ke, Ailong; Weaver, Keith E.; Dunny, Gary M.; ... Show more Show less
MetadataShow full item record
Anti-Q is a small RNA encoded on pCF10, an antibiotic resistance plasmid of Enterococcus faecalis, which negatively regulates conjugation of the plasmid. In this study we sought to understand how Anti-Q is generated relative to larger transcripts of the same operon. We found that Anti-Q folds into a branched structure that functions as a factor-independent terminator. In vitro and in vivo, termination is dependent on the integrity of this structure as well as the presence of a 3′ polyuridine tract, but is not dependent on other downstream sequences. In vitro, terminated transcripts are released from RNA polymerase after synthesis. In vivo, a mutant with reduced termination efficiency demonstrated loss of tight control of conjugation function. A search of bacterial genomes revealed the presence of sequences that encode Anti-Q–like RNA structures. In vitro and in vivo experiments demonstrated that one of these functions as a terminator. This work reveals a previously unappreciated flexibility in the structure of factor-independent terminators and identifies a mechanism for generation of functional small RNAs; it should also inform annotation of bacterial sequence features, such as terminators, functional sRNAs, and operons.
DepartmentMassachusetts Institute of Technology. Department of Biology
Proceedings of the National Academy of Sciences
National Academy of Sciences (U.S.)
Johnson, Christopher M., Yuqing Chen, Heejin Lee, Ailong Ke, Keith E. Weaver, and Gary M. Dunny. “Identification of a Conserved Branched RNA Structure That Functions as a Factor-Independent Terminator.” Proceedings of the National Academy of Sciences 111, no. 9 (February 18, 2014): 3573–3578.
Final published version