| Title: | Direct evidence for control of the pheromone-inducible prgQ operon of Enterococcus faecalis plasmid pCF10 by a countertranscript-driven attenuation mechanism |
| Author(s): | Johnson CM; Manias DA; Haemig HA; Shokeen S; Weaver KE; Henkin TM; Dunny GM; |
| Address: | "Department of Microbiology, University of Minnesota, Minneapolis, Minnesota 55455, USA" |
| ISSN/ISBN: | 1098-5530 (Electronic) 0021-9193 (Print) 0021-9193 (Linking) |
| Abstract: | "The mating response of Enterococcus faecalis cells carrying the conjugative plasmid pCF10 is controlled by multiple regulatory circuits. Initiation of transcription of the prgQ conjugation operon is controlled by the peptide receptor protein PrgX; binding of the pheromone peptide cCF10 to PrgX abolishes PrgX repression, while binding of the inhibitor peptide iCF10 enhances repression. The results of molecular analysis of prgQ transcripts and genetic studies suggested that the elongation of prgQ transcripts past a putative terminator (IRS1) may be controlled by the interaction of nascent prgQ mRNAs with a small antisense RNA (Anti-Q) encoded within prgQ. Direct evidence for interaction of these RNAs, as well as the resulting effects on readthrough of prgQ transcription, has been limited. Here we report the results of experiments that (i) determine the inherent termination properties of prgQ transcripts in the absence of Anti-Q; (ii) determine the direct effects of the interaction of Anti-Q with nascent prgQ transcripts in the absence of complicating effects of the PrgX protein; and (iii) begin to dissect the structural components involved in these interactions. The results confirm the existence of alternative terminating and antiterminating forms of nascent prgQ transcripts in vivo and demonstrate that the interaction of Anti-Q with these transcripts leads to termination via inhibition of antiterminator formation. In vitro transcription assays support the major results of the in vivo studies. The data support a model for Anti-Q function suggested from recent studies of these RNAs and their interactions in vitro (S. Shokeen, C. M. Johnson, T. J. Greenfield, D. A. Manias, G. M. Dunny, and K. E. Weaver, submitted for publication)" |
| Keywords: | "Bacterial Proteins/genetics/*metabolism Base Sequence Enterococcus faecalis/drug effects/*metabolism Gene Expression Regulation, Bacterial/*physiology Pheromones/*pharmacology Protein Sorting Signals/genetics Transcription, Genetic;" |
| Notes: | "MedlineJohnson, Christopher M Manias, Dawn A Haemig, Heather A H Shokeen, Sonia Weaver, Keith E Henkin, Tina M Dunny, Gary M eng GM47823/GM/NIGMS NIH HHS/ R01 GM047823/GM/NIGMS NIH HHS/ GM55544/GM/NIGMS NIH HHS/ GM49530/GM/NIGMS NIH HHS/ R01 GM049530/GM/NIGMS NIH HHS/ R01 GM055544/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural 2010/01/26 J Bacteriol. 2010 Mar; 192(6):1634-42. doi: 10.1128/JB.01525-09. Epub 2010 Jan 22" |
