PamR, a new MarR-like regulator affecting prophages and metabolic genes expression in Bacillus subtilis

Abstract

B. subtilis adapts to changing environments by reprogramming its genetic expression through a variety of transcriptional regulators from the global transition state regulators that allow a complete resetting of the cell genetic expression, to stress specific regulators controlling only a limited number of key genes required for optimal adaptation. Among them, MarR-type transcriptional regulators are known to respond to a variety of stresses including antibiotics or oxidative stress, and to control catabolic or virulence gene expression. Here we report the characterization of the ydcFGH operon of B. subtilis, containing a putative MarR-type transcriptional regulator. Using a combination of molecular genetics and high-throughput approaches, we show that this regulator, renamed PamR, controls directly its own expression and influence the expression of large sets of prophage-related and metabolic genes. The extent of the regulon impacted by PamR suggests that this regulator reprograms the metabolic landscape of B. subtilis in response to a yet unknown signal.

Molecular dissection of the replication system of plasmid pIGRK encoding two in-frame Rep proteins with antagonistic functions

“…Using the BLAST server, a helix-turn-helix (HTH) motif was identified in the central part of the protein. The predicted secondary structure of aa sequences surrounding this putative HTH motif resembles wHTH (winged helix-turn-helix) DNA binding/dimerization motifs of MarR (multiple antibiotic resistances regulator)-like transcriptional regulators [26]. In addition, a putative coiled-coil dimerization motif located in the C -terminal part of RepR [27] was identified using Yaspin software (Fig.…”

“…Rep proteins interactions were analyzed using bacterial two-hybrid system constructed by Di Lallo and co-workers [26]. This system uses the E. coli R721 test strain carrying chromosomally encoded lacZ reporter gene and two expression vectors (both enabling recombinant proteins production from IPTG inducted lacZ promoter).…”

“…If the analyzed proteins, overproduced in translational fusions with the repressor subunits, interact directly with each other, an active hybrid repressor is formed and R721 lacZ promoter activity is inhibited. The measure of dimer formation in this system is therefore the decrease in β-galactosidase activity in comparison with the control strain R721 [26]. Descriptions of the constructed recombinant pcl 22 and pcl 434 vectors are listed in [Additional file 3: Table S2].…”

MreB Forms Subdiffraction Nanofilaments during Active Growth in Bacillus subtilis

“…Samples were collected at an optical density at 600 nm (OD 600 ) indicated on figures, and cell extracts were prepared from cultures grown in LB (supplemented with 20 mM MgSO 4 and 0.5% xylose if required) and loaded on polyacrylamide-SDS gels as previously described (33). Blots were performed, and proteins were detected as described in reference 33 using polyclonal antibodies against MreB or GFP (1:10,000).…”

The MarR-Type Regulator MalR Is Involved in Stress-Responsive Cell Envelope Remodeling in Corynebacterium glutamicum

“…MalR bound to 13 regions within the CGP3 element overall and overexpression of the malR gene counteracted CGP3 induction upon addition of the SOS inducing antibiotic mitomycin C. So far, little is known about the role of MarR-type regulators in the control of horizontally acquired elements. In Bacillus subtilis , a pamR deficient strain displayed altered expression of prophage genes, however the precise regulatory impact remained unclear (De San Eustaquio-Campillo et al, 2017). Another example is depicted by RovA, which is a MarR-type transcription factor in E. coli, Yersinia pseudotuberculosis and its homolog SlyA from Salmonella (Navarre et al, 2007).…”