201
|
Rigali S, Nothaft H, Noens EEE, Schlicht M, Colson S, Müller M, Joris B, Koerten HK, Hopwood DA, Titgemeyer F, van Wezel GP. The sugar phosphotransferase system of Streptomyces coelicolor is regulated by the GntR-family regulator DasR and links N-acetylglucosamine metabolism to the control of development. Mol Microbiol 2006; 61:1237-51. [PMID: 16925557 DOI: 10.1111/j.1365-2958.2006.05319.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Members of the soil-dwelling, sporulating prokaryotic genus Streptomyces are indispensable for the recycling of the most abundant polysaccharides on earth (cellulose and chitin), and produce a wide range of antibiotics and industrial enzymes. How do these organisms sense the nutritional state of the environment, and what controls the signal for the switch to antibiotic production and morphological development? Here we show that high extracellular concentrations of N-acetylglucosamine, the monomer of chitin, prevent Streptomyces coelicolor progressing beyond the vegetative state, and that this effect is absent in a mutant defective of N-acetylglucosamine transport. We provide evidence that the signal is transmitted through the GntR-family regulator DasR, which controls the N-acetylglucosamine regulon, including the pts genes ptsH, ptsI and crr needed for uptake of N-acetylglucosamine. Deletion of dasR or the pts genes resulted in a bald phenotype. Binding of DasR to its target genes is abolished by glucosamine 6-phosphate, a central molecule in N-acetylglucosamine metabolism. Extracellular complementation experiments with many bld mutants showed that the dasR mutant is arrested at an early stage of the developmental programme, and does not fit in the previously described bld signalling cascade. Thus, for the first time we are able to directly link carbon (and nitrogen) metabolism to development, highlighting a novel type of metabolic regulator, which senses the nutritional state of the habitat, maintaining vegetative growth until changing circumstances trigger the switch to sporulation. Our work, and the model it suggests, provide new leads towards understanding how microorganisms time developmental commitment.
Collapse
Affiliation(s)
- Sébastien Rigali
- Department of Biochemistry, Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, the Netherlands
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
202
|
Hillerich B, Westpheling J. A new GntR family transcriptional regulator in streptomyces coelicolor is required for morphogenesis and antibiotic production and controls transcription of an ABC transporter in response to carbon source. J Bacteriol 2006; 188:7477-87. [PMID: 16936034 PMCID: PMC1636292 DOI: 10.1128/jb.00898-06] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We recently reported the isolation and initial characterization of a transposon-generated mutation that resulted in defects in both morphogenesis and antibiotic production in Streptomyces coelicolor. The insertion identified the SCO7168 open reading frame whose predicted product is a GntR family transcriptional regulator. Here, we show that this gene acts to repress transcription of itself as well as a series of genes immediately adjacent to it on the S. coelicolor chromosome that likely encode an ATP-binding cassette (ABC)-type transporter for carbohydrate uptake. Transcription of this transporter is strongly induced by growth on relatively poor carbon sources such as trehalose and melibiose and weakly induced by lactose and glycerol but not glucose, and induction is not repressed by the presence of glucose. Constructed deletions of the ABC transporter itself resulted in the suppression of the original transposon mutation, suggesting that inappropriate expression of the ABC transporter is responsible, at least in part, for the mutant phenotype. Because this transporter responds to the presence of alpha-glucosides and has similarity to two other carbohydrate transporters of this class, we have named the genes of the transporter agl3E, agl3F, and agl3G and the GntR-like protein that regulates transcription of the transporter agl3R in accordance with established nomenclature. We suggest that agl3R is one of a number of homologous proteins in Streptomyces (there are 57 putative GntR family regulators in the S. coelicolor genome) that respond to nutritional and/or environmental signals to control genes that affect morphogenesis and antibiotic production.
Collapse
|
203
|
Straight PD, Willey JM, Kolter R. Interactions between Streptomyces coelicolor and Bacillus subtilis: Role of surfactants in raising aerial structures. J Bacteriol 2006; 188:4918-25. [PMID: 16788200 PMCID: PMC1483000 DOI: 10.1128/jb.00162-06] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using mixed-species cultures, we have undertaken a study of interactions between two common spore-forming soil bacteria, Bacillus subtilis and Streptomyces coelicolor. Our experiments demonstrate that the development of aerial hyphae and spores by S. coelicolor is inhibited by surfactin, a lipopeptide surfactant produced by B. subtilis. Current models of aerial development by sporulating bacteria and fungi postulate a role for surfactants in reducing surface tension at air-liquid interfaces, thereby removing the major barrier to aerial growth. S. coelicolor produces SapB, an amphipathic peptide that is surface active and required for aerial growth on certain media. Loss of aerial hyphae in developmental mutants can be rescued by addition of purified SapB. While a surfactant from a fungus can substitute for SapB in a mutant that lacks aerial hyphae, not all surfactants have this effect. We show that surfactin is required for formation of aerial structures on the surface of B. subtilis colonies. However, in contrast to this positive role, our experiments reveal that surfactin acts antagonistically by arresting S. coelicolor aerial development and causing altered expression of developmental genes. Our observations support the idea that surfactants function specifically for a given organism regardless of their shared ability to reduce surface tension. Production of surfactants with antagonistic activity could provide a powerful competitive advantage during surface colonization and in competition for resources.
Collapse
Affiliation(s)
- Paul D Straight
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Ave., Boston, MA 02115, USA
| | | | | |
Collapse
|
204
|
Hoskisson PA, Rigali S, Fowler K, Findlay KC, Buttner MJ. DevA, a GntR-like transcriptional regulator required for development in Streptomyces coelicolor. J Bacteriol 2006; 188:5014-23. [PMID: 16816174 PMCID: PMC1539961 DOI: 10.1128/jb.00307-06] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Accepted: 04/20/2006] [Indexed: 11/20/2022] Open
Abstract
The gram-positive filamentous bacterium Streptomyces coelicolor has a complex developmental cycle with three distinct phases: growth of the substrate mycelium, development of reproductive structures called aerial hyphae, and differentiation of these aerial filaments into long chains of exospores. During a transposon mutagenesis screen, we identified a novel gene (devA) required for proper development. The devA mutant produced only rare aerial hyphae, and those that were produced developed aberrant spore chains that were much shorter than wild-type chains and had misplaced septa. devA encodes a member of the GntR superfamily, a class of transcriptional regulators that typically respond to metabolite effector molecules. devA forms an operon with the downstream gene devB, which encodes a putative hydrolase that is also required for aerial mycelium formation on R5 medium. S1 nuclease protection analysis showed that transcription from the single devA promoter was temporally associated with vegetative growth, and enhanced green fluorescent protein transcriptional fusions showed that transcription was spatially confined to the substrate hyphae in the wild type. In contrast, devAB transcript levels were dramatically upregulated in a devA mutant and the devA promoter was also active in aerial hyphae and spores in this background, suggesting that DevA might negatively regulate its own production. This suggestion was confirmed by gel mobility shift assays that showed that DevA binds its own promoter region in vitro.
Collapse
Affiliation(s)
- Paul A Hoskisson
- Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, United Kingdom.
| | | | | | | | | |
Collapse
|
205
|
Abstract
Bacteria use a variety of means to communicate with one another and with their eukaryotic hosts. In some cases, social interactions allow bacteria to synchronize the behavior of all of the members of the group and thereby act like multicellular organisms. By contrast, some bacterial social engagements promote individuality among members within the group and thereby foster diversity. Here we explore the molecular mechanisms underpinning some recently discovered bacterial communication systems. These include long- and short-range chemical signaling channels; one-way, two-way, and multi-way communication; contact-mediated and contact-inhibited signaling; and the use and spread of misinformation or, more dramatically, even deadly information.
Collapse
Affiliation(s)
- Bonnie L Bassler
- Howard Hughes Medical Institute and Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
| | | |
Collapse
|
206
|
Willey JM, Willems A, Kodani S, Nodwell JR. Morphogenetic surfactants and their role in the formation of aerial hyphae in Streptomyces coelicolor. Mol Microbiol 2006; 59:731-42. [PMID: 16420347 DOI: 10.1111/j.1365-2958.2005.05018.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Withstanding environmental adversity and seeking optimal conditions for reproduction are basic requirements for the survival of all organisms. Filamentous bacteria of the genus Streptomyces produce a remarkable cell type called the aerial hyphae that is central to its ability to meet both of these challenges. Recent advances have brought about a major shift in our understanding of the cell surface proteins that play important roles in the generation of these cells. Here we review our current understanding of one of these groups of proteins, the morphogenetic surfactants, with emphasis on the SapB protein of Streptomyces coelicolor.
Collapse
Affiliation(s)
- Joanne M Willey
- Department of Biology, Hofstra University, Hempstead, NY 11549, USA.
| | | | | | | |
Collapse
|
207
|
Onaka H, Nakaho M, Hayashi K, Igarashi Y, Furumai T. Cloning and characterization of the goadsporin biosynthetic gene cluster from Streptomyces sp. TP-A0584. MICROBIOLOGY-SGM 2006; 151:3923-3933. [PMID: 16339937 DOI: 10.1099/mic.0.28420-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The biosynthetic gene cluster of goadsporin, a polypeptide antibiotic containing thiazole and oxazole rings, was cloned from Streptomyces sp. TP-A0584. The cluster contains a structural gene, godA, and nine god (goadsporin) genes involved in post-translational modification, immunity and transcriptional regulation. Although the gene organization is similar to typical bacteriocin biosynthetic gene clusters, each goadsporin biosynthetic gene shows low homology to these genes. Goadsporin biosynthesis is initiated by the translation of godA, and the subsequent cyclization, dehydration and acetylation are probably catalysed by godD, godE, godF, godG and godH gene products. godI shows high similarity to the 54 kDa subunit of the signal recognition particle and plays an important role in goadsporin immunity. Furthermore, four goadsporin analogues were produced by site-directed mutagenesis of godA, suggesting that this biosynthesis machinery is used for the heterocyclization of peptides.
Collapse
Affiliation(s)
- Hiroyasu Onaka
- Biotechnology Research Center, Toyama Prefectural University, Imizu, Toyama 939-0398, Japan
| | - Mizuho Nakaho
- Biotechnology Research Center, Toyama Prefectural University, Imizu, Toyama 939-0398, Japan
| | - Keiko Hayashi
- Biotechnology Research Center, Toyama Prefectural University, Imizu, Toyama 939-0398, Japan
| | - Yasuhiro Igarashi
- Biotechnology Research Center, Toyama Prefectural University, Imizu, Toyama 939-0398, Japan
| | - Tamotsu Furumai
- Biotechnology Research Center, Toyama Prefectural University, Imizu, Toyama 939-0398, Japan
| |
Collapse
|
208
|
Patton GC, van der Donk WA. New developments in lantibiotic biosynthesis and mode of action. Curr Opin Microbiol 2006; 8:543-51. [PMID: 16118063 DOI: 10.1016/j.mib.2005.08.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Accepted: 08/15/2005] [Indexed: 11/20/2022]
Abstract
Lantibiotics are a unique class of peptide antibiotics. Recent studies of the proteins involved in the elaborate post-translational modifications of lantibiotics have revealed that these enzymes have relaxed substrate specificity. These modifications include the dehydration of serine and threonine residues followed by the intramolecular addition of cysteine thiols to the unsaturated amino acids to create an intricate polycyclic peptide. The use of peptide engineering in vivo and in vitro has allowed investigation of their biosynthetic machinery. Several members utilize a unique mode of biological action that involves the sequestration of lipid II, a crucial intermediate in peptidoglycan biosynthesis, to form pores in bacterial membranes.
Collapse
Affiliation(s)
- Gregory C Patton
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | | |
Collapse
|
209
|
Abstract
Among the multitude of soil-inhabiting, saprophytic Streptomyces species are a growing number of plant pathogens that cause economically important diseases, including potato scab. Streptomyces scabies is the dominant pathogenic species worldwide, but is only one of many that cause very similar disease symptoms on plants. Molecular genetic analysis is beginning to identify the mechanisms used by plant pathogenic species to manipulate their hosts. The nitrated dipeptide phytotoxin, thaxtomin, inhibits cellulose biosynthesis in expanding plant tissues, stimulates Ca2+ spiking, and causes cell death. A secreted necrogenic protein, Nec1, contributes to virulence on diverse plant species. The thaxtomin biosynthetic genes and nec1 lie on a large mobilizable PAI, along with other putative virulence genes including a cytokinin biosynthetic pathway and a saponinase homolog. The PAI is mobilized during conjugation and site-specifically inserts in the linear chromosome of recipient species, accounting for the emergence of new pathogens in agricultural systems. The recently available genome sequence of S. scabies will accelerate research on host-pathogen interactions.
Collapse
Affiliation(s)
- Rosemary Loria
- Department of Plant Pathology, Cornell University, Ithaca, New York 14853-4203, USA.
| | | | | |
Collapse
|
210
|
Kodani S, Lodato MA, Durrant MC, Picart F, Willey JM. SapT, a lanthionine-containing peptide involved in aerial hyphae formation in the streptomycetes. Mol Microbiol 2005; 58:1368-80. [PMID: 16313622 DOI: 10.1111/j.1365-2958.2005.04921.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The developmentally complex soil microbe Streptomyces tendae secretes a hydrophobic peptide that restored to developmental mutants of S. coelicolor the ability to raise aerial hyphae. The S. tendae peptide, SapT, has a lantibiotic structure and molecular modelling predicts that it is amphiphilic, making it structurally and functionally similar to the SapB peptide produced by S. coelicolor. However, SapT, which bears three beta-methyl lanthionine bridges and one lanthionine bridge and demonstrated limited antibiotic activity, is distinct from SapB. The amphiphilic nature of both SapT and SapB is required for their ability to serve as biosurfactants facilitating the emergence of newly formed aerial hyphae. Remarkably, SapB and SapT, and the fungal hydrophobin SC3 were shown to restore to a SapB-deficient S. coelicolor mutant the capacity to undergo complete morphogenesis, such that the extracellular addition of protein resulted in sporulation. This suggests that the initiation of aerial growth may also indirectly trigger the signal transduction events needed for differentiation. These data imply that the production of morphogenetic peptides may be common among the streptomycetes, but that while their ability to function as biosurfactants is conserved, their specific lantibiotic structure is not. Finally, the identification of a second lanthionine-containing morphogenetic peptide suggests that lantibiotic structure and function may be more diverse than previously thought.
Collapse
Affiliation(s)
- Shinya Kodani
- Department of Biology, Hofstra University, Hempstead, NY 11549, USA
| | | | | | | | | |
Collapse
|
211
|
Abstract
The endospore-forming rhizobacterium Bacillus subtilis- the model system for Gram-positive organisms, is able to produce more than two dozen antibiotics with an amazing variety of structures. The produced anti-microbial active compounds include predominantly peptides that are either ribosomally synthesized and post-translationally modified (lantibiotics and lantibiotic-like peptides) or non-ribosomally generated, as well as a couple of non-peptidic compounds such as polyketides, an aminosugar, and a phospholipid. Here I summarize the structures of all known B. subtilis antibiotics, their biochemistry and genetic analysis of their biosyntheses. An updated summary of well-studied antibiotic regulation pathways is given. Furthermore, current findings are resumed that show roles for distinct B. subtilis antibiotics beyond the "pure" anti-microbial action: Non-ribosomally produced lipopeptides are involved in biofilm and swarming development, lantibiotics function as pheromones in quorum-sensing, and a "killing factor" effectuates programmed cell death in sister cells. A discussion of how these antibiotics may contribute to the survival of B. subtilis in its natural environment is given.
Collapse
Affiliation(s)
- Torsten Stein
- Institut für Mikrobiologie, Johann Wolfgang Goethe-Universität, Marie-Curie-Strasse 9, 60439 Frankfurt/Main, Germany.
| |
Collapse
|
212
|
O'Connor TJ, Nodwell JR. Pivotal roles for the receiver domain in the mechanism of action of the response regulator RamR of Streptomyces coelicolor. J Mol Biol 2005; 351:1030-47. [PMID: 16051268 DOI: 10.1016/j.jmb.2005.06.053] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 06/21/2005] [Accepted: 06/22/2005] [Indexed: 11/26/2022]
Abstract
The response regulator RamR activates expression of the ramCSAB operon, the source of the morphogenetic peptide SapB, and is therefore important for morphogenesis of the bacterium Streptomyces coelicolor. Like most response regulators, RamR consists of an amino-terminal receiver domain and a carboxy-terminal DNA binding domain. Four of five highly conserved active site residues known to be important in other response regulators are present in RamR: D12, D56 (the predicted site of phosphorylation), T84 and K105. Here, we show that in spite of this, RamR did not demonstrate an ability to autophosphorylate in vitro in the presence of small molecule phosphodonors. The unphosphorylated protein behaved as a dimer and bound cooperatively to three sites in the ramC promoter, one with very high affinity and two with lower affinity. On its own, the RamR DNA binding domain could not bind DNA but was able to interfere with the action of full length RamR in a manner suggesting direct protein-protein contact. Surprisingly, substitution of residues D12 or T84 had no effect on RamR function in vivo. In contrast, D56A and K105A substitutions caused defects in both dimer formation and DNA binding while the more conservative substitution, D56N permitted dimer formation but not DNA binding. L102 in RamR corresponds to a well-conserved tyrosine (or aromatic) residue that is important for function in the other response regulators. While a L102Y variant, which introduced the aromatic side-chain usually found at this position, functioned normally, L102A and L102W substitutions blocked RamR function in vivo. We show that these substitutions specifically impaired cooperative DNA binding by RamR at the lower affinity recognition sequences. The biochemical properties of RamR therefore differ markedly from those of other well-characterized response regulators.
Collapse
Affiliation(s)
- Tamara J O'Connor
- Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, 1200 Main St W. Hamilton, Ont., Canada L8N 3Z5
| | | |
Collapse
|
213
|
Affiliation(s)
- Karen L Visick
- Department of Biology, 1001 E. 3rd St., Jordan Hall 142, Indiana University, Bloomington, IN 47405, USA
| | | |
Collapse
|
214
|
Chatterjee C, Paul M, Xie L, van der Donk WA. Biosynthesis and mode of action of lantibiotics. Chem Rev 2005; 105:633-84. [PMID: 15700960 DOI: 10.1021/cr030105v] [Citation(s) in RCA: 563] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Champak Chatterjee
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois, USA
| | | | | | | |
Collapse
|
215
|
Albano M, Smits WK, Ho LTY, Kraigher B, Mandic-Mulec I, Kuipers OP, Dubnau D. The Rok protein of Bacillus subtilis represses genes for cell surface and extracellular functions. J Bacteriol 2005; 187:2010-9. [PMID: 15743949 PMCID: PMC1064057 DOI: 10.1128/jb.187.6.2010-2019.2005] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rok is a repressor of the transcriptional activator ComK and is therefore an important regulator of competence in Bacillus subtilis (T. T. Hoa, P. Tortosa, M. Albano, and D. Dubnau, Mol. Microbiol. 43:15-26, 2002). To address the wider role of Rok in the physiology of B. subtilis, we have used a combination of transcriptional profiling, gel shift experiments, and the analysis of lacZ fusions. We demonstrate that Rok is a repressor of a family of genes that specify membrane-localized and secreted proteins, including a number of genes that encode products with antibiotic activity. We present evidence for the recent introduction of rok into the B. subtilis-Bacillus licheniformis-Bacilllus amyloliquefaciens group by horizontal transmission.
Collapse
Affiliation(s)
- Mark Albano
- Public Health Research Institute, Newark, NJ 07103, USA
| | | | | | | | | | | | | |
Collapse
|
216
|
Hunt AC, Servín-González L, Kelemen GH, Buttner MJ. The bldC developmental locus of Streptomyces coelicolor encodes a member of a family of small DNA-binding proteins related to the DNA-binding domains of the MerR family. J Bacteriol 2005; 187:716-28. [PMID: 15629942 PMCID: PMC543565 DOI: 10.1128/jb.187.2.716-728.2005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The bldC locus, required for formation of aerial hyphae in Streptomyces coelicolor, was localized by map-based cloning to the overlap between cosmids D17 and D25 of a minimal ordered library. Subcloning and sequencing showed that bldC encodes a member of a previously unrecognized family of small (58- to 78-residue) DNA-binding proteins, related to the DNA-binding domains of the MerR family of transcriptional activators. BldC family members are found in a wide range of gram-positive and gram-negative bacteria. Constructed DeltabldC mutants were defective in differentiation and antibiotic production. They failed to form an aerial mycelium on minimal medium and showed severe delays in aerial mycelium formation on rich medium. In addition, they failed to produce the polyketide antibiotic actinorhodin, and bldC was shown to be required for normal and sustained transcription of the pathway-specific activator gene actII-orf4. Although DeltabldC mutants produced the tripyrrole antibiotic undecylprodigiosin, transcripts of the pathway-specific activator gene (redD) were reduced to almost undetectable levels after 48 h in the bldC mutant, in contrast to the bldC+ parent strain in which redD transcription continued during aerial mycelium formation and sporulation. This suggests that bldC may be required for maintenance of redD transcription during differentiation. bldC is expressed from a single promoter. S1 nuclease protection assays and immunoblotting showed that bldC is constitutively expressed and that transcription of bldC does not depend on any of the other known bld genes. The bldC18 mutation that originally defined the locus causes a Y49C substitution that results in instability of the protein.
Collapse
Affiliation(s)
- Alison C Hunt
- Department of Molecular Microbiology, John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom
| | | | | | | |
Collapse
|
217
|
Elliot MA, Talbot NJ. Building filaments in the air: aerial morphogenesis in bacteria and fungi. Curr Opin Microbiol 2005; 7:594-601. [PMID: 15556031 DOI: 10.1016/j.mib.2004.10.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To disperse their spores to new sites, filamentous fungi and bacteria need to erect aerial filaments, which develop into fruiting bodies and spore-bearing structures. The first challenge to aerial development is breaking surface tension at an aqueous-air interface, and in both groups of microorganisms, surface-active proteins take part in the initiation of aerial morphogenesis. Comparative analysis of fungi and bacteria is providing new insights into the means by which aerial filamentation is accomplished.
Collapse
Affiliation(s)
- Marie A Elliot
- Department of Molecular Microbiology, John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK.
| | | |
Collapse
|
218
|
Ueda K, Takano H, Nishimoto M, Inaba H, Beppu T. Dual transcriptional control of amfTSBA, which regulates the onset of cellular differentiation in Streptomyces griseus. J Bacteriol 2005; 187:135-42. [PMID: 15601697 PMCID: PMC538820 DOI: 10.1128/jb.187.1.135-142.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The amf gene cluster encodes a probable secretion system for a peptidic morphogen, AmfS, which induces aerial mycelium formation in Streptomyces griseus. Here we examined the transcriptional control mechanism for the promoter preceding amfT (PamfT) directing the transcription of the amfTSBA operon. High-resolution S1 analysis mapped a transcriptional start point at 31 nucleotides upstream of the translational start codon of amfT. Low-resolution analysis showed that PamfT is developmentally regulated in the wild type and completely abolished in an amfR mutant. The -35 region of PamfT contained the consensus sequence for the binding of BldD, a pleiotropic negative regulator for morphological and physiological development in Streptomyces coelicolor A3(2). The cloned bldD locus of S. griseus showed high sequence similarity to the S. coelicolor counterpart. Transcription of bldD occurred constitutively in both the wild type and an A-factor-deficient mutant of S. griseus, which suggests that the regulatory role of BldD is independent of A-factor. The gel retardation assay revealed that purified BldD and AmfR recombinant proteins specifically bind PamfT. Overproduction of BldD in the wild-type cell conferred a bald phenotype (defective in aerial growth and streptomycin production) and caused marked repression of PamfT activity. An amfT-depleted mutant also showed a bald phenotype but PamfT activity was not affected. Both the bldD-overproducing wild-type strain and the amfT mutant were unable to induce aerial growth of an amfS mutant in a cross-feeding assay, which indicates that these strains are defective in the production of an active AmfS peptide. The results overall suggests that two independent regulators, AmfR and BldD, control PamfT activity via direct binding to determine the transcriptional level of the amf operon responsible for the production and secretion of AmfS peptide, which induces the erection of aerial hyphae in S. griseus.
Collapse
Affiliation(s)
- Kenji Ueda
- Life Science Research Center, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa 252-8510, Japan.
| | | | | | | | | |
Collapse
|
219
|
van Wezel GP, Vijgenboom E. Novel Aspects of Signaling in Streptomyces Development. ADVANCES IN APPLIED MICROBIOLOGY 2004; 56:65-88. [PMID: 15566976 DOI: 10.1016/s0065-2164(04)56002-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Gilles P van Wezel
- Department of Biochemistry, Leiden Institute of Chemistry 2300RA Leiden, The Netherlands.
| | | |
Collapse
|