| Title: | "Structural Differences in Complexes between the Master Regulator PrgX, Peptide Pheromones, and Operator Binding Sites Determine the Induction State for Conjugative Transfer of pCF10" |
| Author(s): | Segawa T; Manias DA; Dunny GM; |
| Address: | "Department of Microbiology and Immunology, University of Minnesota Medical Schoolgrid.471402.4, Minneapolis, Minnesota, USA" |
| ISSN/ISBN: | 1098-5530 (Electronic) 0021-9193 (Print) 0021-9193 (Linking) |
| Abstract: | "Pheromone-inducible conjugation in the Enterococcus faecalis pCF10 system is regulated by the PrgX transcription factor through binding interactions at two operator binding sites (XBS1 and XBS2) upstream of the transcription start site of the prgQ operon encoding the conjugation machinery. Repression of transcription requires the interaction of a PrgX tetramer with both XBSs via formation of a DNA loop. The ability of PrgX to regulate prgQ transcription is modulated by its interaction with two antagonistic regulatory peptides, ICF10 (I) and cCF10 (C); the former peptide inhibits prgQ transcription, while the latter peptide enhances prgQ transcription. In this report, we used electrophoretic mobility shift assays (EMSAs) and DNase footprinting to examine binding interactions between the XBS operator sites and various forms of PrgX (Apo-X, PrgX/I, and PrgX/C). Whereas a previous model based on high-resolution structures of PrgX proposed that the functional differences between PrgX/C and PrgX/I resulted from differences in PrgX oligomerization state, the current results show that specific differences in XBS2 occupancy by bound tetramers account for the differential regulatory properties of the two peptide/PrgX complexes and for the effects of XBS mutations on regulation. The results also confirmed a DNA looping model of PrgX function. IMPORTANCE Peptide pheromones regulate antibiotic resistance transfer in Enterococcus faecalis. Here, we present new data showing that pheromone-dependent regulation of transfer genes is mediated via effects on the structures of complexes between peptides, the intracellular peptide receptor, and operator sites on the target DNA" |
| Keywords: | "*Peptides/metabolism Binding Sites *Transcription Factors/metabolism Mutation Pheromones/metabolism Enterococcus faecalis/metabolism Plasmids Conjugation, Genetic Bacterial Proteins/metabolism antibiotic resistance cell-cell signaling gene transfer sex ph;" |
| Notes: | "MedlineSegawa, Takaya Manias, Dawn A Dunny, Gary M eng R35GM118079/HHS | NIH | National Institute of General Medical Sciences (NIGMS)/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't 2022/11/11 J Bacteriol. 2022 Dec 20; 204(12):e0029822. doi: 10.1128/jb.00298-22. Epub 2022 Nov 10" |
