« Previous AbstractDirect evidence for control of the pheromone-inducible prgQ operon of Enterococcus faecalis plasmid pCF10 by a countertranscript-driven attenuation mechanism    Next AbstractLet Me Upgrade You: Impact of Mobile Genetic Elements on Enterococcal Adaptation and Evolution »

Proc Natl Acad Sci U S A

Title:		Identification of a conserved branched RNA structure that functions as a factor-independent terminator
Author(s):		Johnson CM; Chen Y; Lee H; Ke A; Weaver KE; Dunny GM;
Address:		"Department of Microbiology, University of Minnesota, Minneapolis, MN 55455"
Journal Title:		Proc Natl Acad Sci U S A
Year:		2014
Volume:		20140218
Issue:		9
Page Number:		3573 - 3578
DOI:		10.1073/pnas.1315374111
ISSN/ISBN:		1091-6490 (Electronic) 0027-8424 (Print) 0027-8424 (Linking)
Abstract:		"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"
Keywords:		"Base Sequence Blotting, Northern Blotting, Western Conjugation, Genetic/genetics/*physiology Enterococcus faecalis/*genetics Molecular Sequence Data Mutagenesis Plasmids/*genetics RNA Folding/genetics RNA, Bacterial/*genetics Real-Time Polymerase Chain Re;"
Notes:		"MedlineJohnson, Christopher M Chen, Yuqing Lee, Heejin Ke, Ailong Weaver, Keith E Dunny, Gary M eng R01 GM049530/GM/NIGMS NIH HHS/ GM49530/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural 2014/02/20 Proc Natl Acad Sci U S A. 2014 Mar 4; 111(9):3573-8. doi: 10.1073/pnas.1315374111. Epub 2014 Feb 18"