By using the previously established Escherichia coli two-plasmid system, we identified a promoter recognized by the Streptomyces coelicolor A3(2) stress-response sigma factor sigmaH. The promoter directed expression of the sigJ gene encoding an extracytoplasmic function (ECF) sigma factor. S1-nuclease mapping using RNA prepared from E. coli containing the two-plasmid system, and S. coelicolor A3(2) from various developmental stages identified an identical transcription start point in both strains, corresponding to the sigJp promoter. The sigJp promoter was induced during sporulation of aerial hyphae. The level of the transcript from sigJp was dramatically reduced in a S. coelicolor A3(2) sigH mutant and unaffected in a sigF mutant. The S. coelicolor A3(2) core RNA polymerase, after complementation with sigmaH, was able to recognize the sigJp promoter in vitro. A sigJ mutation had no obvious effect on growth, stress response, differentiation, and production of antibiotics. The results suggested that the S. coelicolor A3(2) sigJ gene is under the control of stress-response sigmaH, thus indicating a cascade of sigma factors in Streptomyces stress response and development. Considering the expression of sigJ and its direct dependence upon developmentally-regulated sigmaH, we assume that sigmaJ may play a role in the later stages of development of S. coelicolor A3(2).
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http://dx.doi.org/10.1007/s00203-006-0158-9 | DOI Listing |
Microb Cell Fact
December 2024
Xiangya International Academy of Translational Medicine, Central South University, Tongzipo Road, #172, Yuelu District, Changsha, Hunan, 410013, China.
Background: Universal stress proteins (USPs) are prevalent in various bacteria to cope with different adverse stresses, while their possible effects on secondary metabolisms of hosts are unclear. Tiancimycins (TNMs) are ten-membered endiynes possessing excellent potential for development of anticancer antibody-drug conjugates. During our efforts to improve TNMs titer, a high-producing strain Streptomyces sp.
View Article and Find Full Text PDFCurr Microbiol
December 2024
Faculty of Science, Molecular Biology and Genetics Department, Gebze Technical University, Gebze, 41400, Kocaeli, Türkiye.
The genus Streptomyces is a group of gram-positive bacteria that exhibit a distinctive growth pattern characterised by elongated, branched hyphae. Streptomyces coelicolor A3(2), which produces at least five different antibiotics, is a model organism that is widely used in genetic studies. There are very few studies in Streptomyces on the ATP-dependent Lon protease, which has very important functions in every organism and is particularly responsible for protein homeostasis.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
December 2024
Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114, Wroclaw, Poland.
Coelimycin (CPK) producer Streptomyces coelicolor A3(2) is a well-established model for the genetic studies of bacteria from the genus Streptomyces, renowned for their ability to produce a plethora of antibiotics and other secondary metabolites. Expression regulation of natural product biosynthetic gene clusters (BGCs) is highly complex, involving not only regulatory proteins, like transcription factors, but also the products of the biosynthetic pathway that may act as ligands for some regulators and modulate their activity. Here, we present the evidence that intracellular CPK precursor(s) (preCPK) is involved in a negative feedback loop repressing the CPK BGC.
View Article and Find Full Text PDFArch Microbiol
September 2024
Faculty of Science, Molecular Biology and Genetics Department, Gebze Technical University, Gebze, Kocaeli, 41400, Turkey.
The bacterial stringent response is a global regulatory process in which polyphosphate kinase (Ppk) and lon protease are important players. Previous studies have shown that overexpression of the lon gene and deletion of the ppk gene significantly increased actinorhodin production in Streptomyces coelicolor (SCO). In this study, a recombinant SCOΔppk-lon cell, expressing the extra lon gene in Δppk cells, was simulated using a modified in silico (computational) model, ecSco-GEM, and the negative effect of Ppk on actinorhodin production was confirmed.
View Article and Find Full Text PDFCurr Res Microb Sci
August 2024
Université de Reims Champagne Ardennes, INRAE, FARE, UMR A 614, Chaire AFERE, 51097 Reims, France.
Long seen as non-valorisable waste, agricultural co-products are increasingly used in biorefinery processes. Co-culture appears as new trend for to improve the degradation of lignocellulose and improve the production of bioproducts. The goal of the study was to setup inter-domain co-cultures with high capabilities of lignocellulose degradation using a pluridisciplinary approach combining bioinformatics, enzymology, transcriptomics.
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