The alternative stress response sigma factor σ(H) has a role in regulation of the osmotic stress response and in morphological differentiation in Streptomyces coelicolor A3(2). Its gene, sigH, is located in an operon with the gene that encodes its anti-sigma factor UshX (PrsH). However, no gene with similarity to an anti-anti-sigma factor which may have a role in σ(H) activation by a "partner-switching" mechanism is located in the operon. By using a combination of several approaches, including pull-down and bacterial two-hybrid assays and visualization of the complex by native polyacrylamide electrophoresis, we demonstrated a direct interaction between UshX and the pleiotropic sporulation-specific anti-anti-sigma factor BldG. Osmotic induction of transcription of the sigHp2 promoter that is specifically recognized by RNA polymerase containing σ(H) was absent in an S. coelicolor bldG mutant, indicating a role of BldG in σ(H) activation by a partner-switching-like mechanism.
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http://dx.doi.org/10.1128/JB.00828-10 | DOI Listing |
Front Bioeng Biotechnol
November 2024
Marbio, Faculty for Fisheries, Biosciences and Economy, UiT-The Arctic University of Norway, Tromsø, Norway.
As the natural producer of acarbose, sp. SE50/110 has high industrial relevance. Like most Actinobacteria, the strain carries several more putative biosynthetic gene clusters (BGCs) to produce further natural products, which are to be discovered.
View Article and Find Full Text PDFMicrobiol Spectr
October 2024
Molecular Biology, Microbiology and Biochemistry Graduate Program, Southern Illinois University Carbondale, Carbondale, Illinois, USA.
Partner switching mechanisms (PSMs) are signal transduction systems comprised of a sensor phosphatase (RsbU), an anti-sigma factor (RsbW, kinase), an anti-anti-sigma factor (RsbV, the RsbW substrate), and a target sigma factor. spp. are obligate intracellular bacterial pathogens of animals that undergo a developmental cycle transitioning between the infectious elementary body (EB) and replicative reticulate body (RB) within a host cell-derived vacuole (inclusion).
View Article and Find Full Text PDFBiology (Basel)
August 2024
Laboratory of Bioinformatics, Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
is a model organism used to study molecular processes in Gram-positive bacteria. Sigma factor B, which associates with RNA polymerase, is one of the transcriptional regulators involved in the cell's response to environmental stress. Experiments have proven that the amounts of free σ (SigB) are controlled by a system of anti- (RsbW) and anti-anti-sigma (RsbV) factors expressed from the same operon as SigB.
View Article and Find Full Text PDFJ Biol Chem
September 2024
Department of Biochemistry, Brandeis University, Waltham, Massachusetts, USA. Electronic address:
How protein phosphatases achieve specificity for their substrates is a major outstanding question. PPM family serine/threonine phosphatases are widespread in bacteria and eukaryotes, where they dephosphorylate target proteins with a high degree of specificity. In bacteria, PPM phosphatases control diverse transcriptional responses by dephosphorylating anti-anti-sigma factors of the STAS domain family, exemplified by Bacillus subtilis phosphatases SpoIIE, which controls cell-fate during endospore formation, and RsbU, which initiates the general stress response.
View Article and Find Full Text PDFmBio
February 2024
Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA.
(Mtb) can adopt a non-growing dormant state during infection that may be critical to both active and latent tuberculosis. During dormancy, Mtb is widely tolerant toward antibiotics, a significant obstacle in current anti-tubercular drug regimens, and retains the ability to persist in its environment. We aimed to identify novel mechanisms that permit Mtb to survive dormancy in an carbon starvation model using transposon insertion sequencing and gene expression analysis.
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