1
|
Takano H, Asano K, Beppu T, Ueda K. Role of σH paralogs in intracellular melanin formation and spore development in Streptomyces griseus. Gene 2007; 393:43-52. [PMID: 17346906 DOI: 10.1016/j.gene.2007.01.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Revised: 01/11/2007] [Accepted: 01/18/2007] [Indexed: 10/23/2022]
Abstract
Streptomyces griseus possesses multiple stress-response sigma factors including sigma(H). Previously, we have suggested that sigma(H) and related sigma factors are involved in the developmental control of S. griseus. Herein, we studied the role of two sigma(H) paralogs--sigma(F) and sigma(N)--which are encoded in tandem coding sequences of sigF-sigN in S. griseus [sigma(N) has been described as sigma(L) previously (Gene 320:127, 2003)]. A sigF mutant produced decreased levels of intracellular melanin and formed irregular spores. A triple mutant for sigHNF exhibited defective melanin production. While sigN was transcribed by three tandem promoters during the early to late growth phases, sigF was transcribed in the late developmental phase by a single promoter. The activity of the promoter preceding the rpp operon (Prpp), which is responsible for the intracellular melanin biosynthesis, was decreased in the sigF mutant and abolished in the sigHNF, adpA and A-factor biosynthesis mutants. The in vitro transcription assay demonstrated that Esigma(F) transcribed the rpp promoter. Both Esigma(F) and Esigma(N) transcribed a sigma(H)-dependent promoter that preceded the sigH operon, and their activities were repressed by the addition of RshA, an anti-sigma(H) protein. Overall, the results suggest that the three sigma factors have similar functions and that they are required for spore development and pigmentation. The transcription of the rpp operon is regulated both by the stress-response sigma factors and the A-factor regulatory cascade.
Collapse
Affiliation(s)
- Hideaki Takano
- Life Science Research Center, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa 252-8510, Japan
| | | | | | | |
Collapse
|
2
|
Evangelista-Martínez Z, González-Cerón G, Servín-González L. A conserved inverted repeat, the LipR box, mediates transcriptional activation of the Streptomyces exfoliatus lipase gene by LipR, a member of the STAND class of P-loop nucleoside triphosphatases. J Bacteriol 2006; 188:7082-9. [PMID: 17015647 PMCID: PMC1636227 DOI: 10.1128/jb.00896-06] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Expression of the Streptomyces exfoliatus lipA gene, which encodes an extracellular lipase, depends on LipR, a transcriptional activator that belongs to the STAND class of P-loop nucleoside triphosphatases. LipR is closely related to activators present in some antibiotic biosynthesis clusters of actinomycetes, forming the LipR/TchG family of regulators. In this work we showed that purified LipR protein is essential for activation of lipA transcription in vitro and that this transcription depends on the presence of a conserved inverted repeat, the LipR box, located upstream of the lipA promoter. Mutagenesis of the lipA promoter region indicated that most transcription depends on LipR binding to the proximal half-site of the LipR box in close proximity to the -35 region of the promoter. Our experiments also indicated that LipR establishes contact with the RNA polymerase on both sides of the LipR box, since some activation was observed when only the distal half-site was present or when the entire LipR box was moved further upstream. We also showed that the LipR proteins of S. exfoliatus and Streptomyces coelicolor are functionally interchangeable both in vitro and in vivo, revealing the functional conservation of the regulatory elements in these two species.
Collapse
|
3
|
Mukherjee R, Chatterji D. Evaluation of the role of sigma B in Mycobacterium smegmatis. Biochem Biophys Res Commun 2005; 338:964-72. [PMID: 16248983 DOI: 10.1016/j.bbrc.2005.10.038] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2005] [Accepted: 10/07/2005] [Indexed: 11/24/2022]
Abstract
The alternate sigma factor, sigB, is known to play a crucial role in maintaining the stationary phase in mycobacteria. In this communication, we have studied the proteomics of Mycobacterium smegmatis mc(2)155 and its two derivatives, one of which has a disrupted sigB gene and the other, PMVSigB, which contains a multicopy plasmid containing sigB. We have identified by two-dimensional gel analyses, several proteins that are over-expressed in PMVSigB compared to mc(2)155. These proteins are either stress proteins or participate actively in different metabolic pathways of the organisms. On the other hand, when sigB deleted mycobacteria were grown until the stationary phase and its two-dimensional protein profile was compared to that of mc(2)155, few DNA binding proteins were found to be up-regulated. We have shown recently that upon over-expressing sigB, the cell surface glycopeptidolipids of M. smegmatis are hyperglycosylated, a situation similar to what was observed for nutritionally starved bacteria. Gene expression profile through quantitative PCR presented here identified a Rhamnosyltransferase responsible for this hyperglycosylation.
Collapse
Affiliation(s)
- Raju Mukherjee
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | | |
Collapse
|
4
|
Doull JL, Vining LC. Physiology of antibiotic production in actinomycetes and some underlying control mechanisms. Biotechnol Adv 2003; 8:141-58. [PMID: 14545908 DOI: 10.1016/0734-9750(90)90010-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Some of the accumulated information on the physiology and nutritional control of antibiotic production in actinomycetes can now be related to recent discoveries in the field of actinomycete molecular biology. This review focuses on aspects of genetic and metabolic control of antibiotic biosynthesis. It surveys some well established principles in the relationship between primary and secondary metabolism, and summarizes briefly the areas where progress is being made in elucidating the molecular organization of regulatory systems underlying this relationship.
Collapse
Affiliation(s)
- J L Doull
- Biology Department, Dalhousie University, Halifax, Nova Scotia, Canada
| | | |
Collapse
|
5
|
Abstract
Overproduction of microbial metabolites is related to developmental phases of microorganisms. Inducers, effectors, inhibitors and various signal molecules play a role in different types of overproduction. Primary and secondary metabolism are interconnected. Biosynthesis of enzymes catalyzing metabolic reactions in microbial cells is controlled by well-known positive and negative mechanisms, e.g. induction, repression, catabolite repression, mechanisms controlling enzyme activity include isosteric and allosteric interactions, e.g. competitive and non-competitive inhibition, allosteric effects, molecular conversion etc. Biosynthesis of secondary metabolites is catalyzed by unaltered enzymes of primary metabolism, by altered enzymes of primary metabolism and by specific enzymes of secondary metabolism. In addition to classical mutagenesis and selection of suitable microbial cells, methods of molecular genetics are used in the overproduction of microbial products.
Collapse
Affiliation(s)
- Z Vanek
- Institute of Microbiology, Czechoslovak Academy of Sciences, Prague, Czechoslovakia
| | | | | |
Collapse
|
6
|
Viollier PH, Kelemen GH, Dale GE, Nguyen KT, Buttner MJ, Thompson CJ. Specialized osmotic stress response systems involve multiple SigB-like sigma factors in Streptomyces coelicolor. Mol Microbiol 2003; 47:699-714. [PMID: 12535070 DOI: 10.1046/j.1365-2958.2003.03302.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Whereas in Bacillus subtilis, a general stress response stimulon under the control of a single sigma factor (SigB) is induced by different physiological and environmental stresses (heat, salt or ethanol shock), in Streptomyces coelicolor, these environmental stresses induce independent sets of proteins, and its genome encodes nine SigB paralogues. To investigate possible functions of multiple sigB-like genes in S. coelicolor, Pctc, a promoter routinely used to assay SigB activity in vivo, was analysed as a heterologous reporter. The fact that Pctc was activated by osmotic shock, but not by heat or ethanol, confirmed that stress response system(s) could operate independently in S. coelicolor. Pctc was also induced transiently during growth of liquid cultures, presumably by nutritional signals. We purified an RNA polymerase holoenzyme from crude extracts that catalysed specific transcription of Pctc in vitro. Its sigma subunit was identified as a product of the sigH gene, which is co-transcribed downstream of a putative antisigma factor gene (prsH). Although the sigH function was not needed for normal colony morphology, prsH was conditionally required for both aerial hyphae formation and regulation of antibiotic biosynthesis. Levels of two different sigH-encoded proteins were growth phase dependent but not significantly changed by osmotic stress, implying the important roles of post-translational regulatory elements such as PrsH. In addition, synthesis of three other SigH-like proteins was induced by osmotic stress, but not by ethanol or heat. Two of them were genetically assigned to sigH homologous loci sigI and sigJ and shown to be independently regulated. This family of SigH-like proteins displayed different osmotic response kinetics. Thus, in contrast to many other bacteria, S. coelicolor uses an osmotic sensory system that can co-ordinate the activity of multiple paralogues to control the relative activity of promoters within the same stress stimulon. Such specialized stress response systems may reflect adaptive functions needed for colonial differentiation.
Collapse
Affiliation(s)
- Patrick H Viollier
- Division of Molecular Microbiology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland
| | | | | | | | | | | |
Collapse
|
7
|
Viollier PH, Weihofen A, Folcher M, Thompson CJ. Post-transcriptional regulation of the Streptomyces coelicolor stress responsive sigma factor, SigH, involves translational control, proteolytic processing, and an anti-sigma factor homolog. J Mol Biol 2003; 325:637-49. [PMID: 12507469 DOI: 10.1016/s0022-2836(02)01280-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The sigH gene encodes a sigma factor whose transcription is controlled by stress regulatory systems and the developmental program in Streptomyces coelicolor. Here, we describe developmentally regulated post-transcriptional control systems for SigH. sigH is expressed as three primary translation products, SigH-sigma(37), SigH-sigma(51), and SigH-sigma(52). In vitro, SigH-sigma(52) was comparable to SigH-sigma(37) in its ability to associate with RNA polymerase core enzyme and specifically initiate transcription in vitro. While SigH-sigma(51/52) were the primary gene products observed throughout early phases of growth, their abundance decreased during later stages in liquid or solid phase cultures while levels of shorter, C-terminally encoded products increased. These included SigH-sigma(37), a product of the downstream translational initiation site, as well as two proteolytic derivatives of SigH-sigma(51/52) (34kDa and 38kDa). Accumulation of SigH-sigma(37) and processing of SigH-sigma(51/52) into these stable 34kDa and 38kDa derivatives correlated with morphological changes on solid medium and physiological maturation in liquid medium. SigH-sigma(51/52) processing did not occur on medium non-permissive for aerial mycelium formation or in one particular developmental mutant (brgA). The proteolytic activity could be detected in vitro using crude extracts of stationary phase cultures, but was absent from exponential phase cultures. prsH, the gene upstream of sigH having sequence similarity to known anti-sigma factors, was able to bind to, and thus presumably inactivate SigH-sigma(52), SigH-sigma(51), and SigH-sigma(37). We have shown elsewhere that prsH was conditionally required for colonial development. Thus, while at least one transcriptional regulator is known to bring about the accumulation of sigH mRNA at different times and different locations in colonies, the post-transcriptional processes described here regulate the activity of different SigH isoforms and program their temporal accumulation pattern, i.e. the elimination of SigH-sigma(51/52) and accumulation of SigH-sigma(37)-like proteins, as a function of development.
Collapse
Affiliation(s)
- Patrick H Viollier
- Department of Developmental Biology, Beckman Center, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305-5329, USA
| | | | | | | |
Collapse
|
8
|
Sevcikova B, Kormanec J. Activity of the Streptomyces coelicolor stress-response sigma factor sigmaH is regulated by an anti-sigma factor. FEMS Microbiol Lett 2002; 209:229-35. [PMID: 12007810 DOI: 10.1111/j.1574-6968.2002.tb11136.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The alternative sigma factor sigmaH has been shown to play an important role in stress response and morphological differentiation in Streptomyces coelicolor. Its gene, sigH, is located in an operon with the gene encoding proposed anti-sigma factor UshX, and one of the promoters directing expression of the operon is dependent upon sigH. To clarify the function of S. coelicolor UshX, both the sigmaH and UshX proteins were overproduced in Escherichia coli and purified. In an in vitro transcription assay, sigmaH, after complementation with S. coelicolor core RNA polymerase, was able to recognize the sigH-dependent promoter, sigH-P2. This transcription was inhibited by UshX, if it was incubated with sigmaH prior to the addition of the core RNA polymerase. When sigmaH and UshX were incubated and electrophoresed through non-denaturing polyacrylamide gels, they formed a specific complex. These results showed that UshX is a specific anti-sigma factor for sigmaH, and the S. coelicolor sigH operon is directly autoregulated.
Collapse
Affiliation(s)
- Beatrica Sevcikova
- Institute of Molecular Biology, Slovak Academy of Sciences, Dubravska cesta 21, 842 51 Bratislava, Slovak Republic
| | | |
Collapse
|
9
|
Cho YH, Lee EJ, Ahn BE, Roe JH. SigB, an RNA polymerase sigma factor required for osmoprotection and proper differentiation of Streptomyces coelicolor. Mol Microbiol 2001; 42:205-14. [PMID: 11679079 DOI: 10.1046/j.1365-2958.2001.02622.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A gene (sigB) encoding an alternative sigma factor sigmaB in Streptomyces coelicolor A3(2) was isolated and characterized. It encodes a polypeptide of 281 amino acids (31 546 Da) and is highly homologous to Bacillus subtilis sigmaB. The sigB coding region is preceded by four open reading frames (ORFs): dpsA, orfA, rsbB and rsbA in sequential order. RNA analyses revealed that rsbB, rsbA and sigB constitute an operon (sigB operon). Transcripts were produced constitutively from a promoter (sigBp2) upstream of the rsbB coding region, contributing to the basal level expression of sigmaB protein. An inducible promoter (sigBp1) resembling the catB promoter (catBp) was located between the rsbA and sigB coding regions. Transcripts from sigBp1 dramatically increased as cells differentiated on solid media, at the stationary phase in liquid media or by osmotic stresses similar to the behaviour of catBp transcripts. Both catBp and sigBp1 promoters were recognized specifically by sigmaB-containing RNA polymerase in vitro. Disruption of the sigB gene abolished not only the differentiation-associated expression but also the osmotic induction of the catB gene, indicating that catBp is under the control of sigmaB. The sigB mutant exhibited a similar phenotype to the catB mutant, being sensitive to hyperosmolarity, blocked in forming aerial mycelium and with skewed antibiotic production. Therefore, we conclude that sigmaB ensures the proper differentiation and osmoprotection of S. coelicolor cells, primarily via regulation of the expression of catalase B.
Collapse
Affiliation(s)
- Y H Cho
- Laboratory of Molecular Microbiology, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Korea
| | | | | | | |
Collapse
|
10
|
Kelemen GH, Viollier PH, Tenor J, Marri L, Buttner MJ, Thompson CJ. A connection between stress and development in the multicellular prokaryote Streptomyces coelicolor A3(2). Mol Microbiol 2001; 40:804-14. [PMID: 11401688 DOI: 10.1046/j.1365-2958.2001.02417.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Morphological changes leading to aerial mycelium formation and sporulation in the mycelial bacterium Streptomyces coelicolor rely on establishing distinct patterns of gene expression in separate regions of the colony. sigmaH was identified previously as one of three paralogous sigma factors associated with stress responses in S. coelicolor. Here, we show that sigH and the upstream gene prsH (encoding a putative antisigma factor of sigmaH) form an operon transcribed from two developmentally regulated promoters, sigHp1 and sigHp2. While sigHp1 activity is confined to the early phase of growth, transcription of sigHp2 is dramatically induced at the time of aerial hyphae formation. Localization of sigHp2 activity using a transcriptional fusion to the green fluorescent protein reporter gene (sigHp2-egfp) showed that sigHp2 transcription is spatially restricted to sporulating aerial hyphae in wild-type S. coelicolor. However, analysis of mutants unable to form aerial hyphae (bld mutants) showed that sigHp2 transcription and sigmaH protein levels are dramatically upregulated in a bldD mutant, and that the sigHp2-egfp fusion was expressed ectopically in the substrate mycelium in the bldD background. Finally, a protein possessing sigHp2 promoter-binding activity was purified to homogeneity from crude mycelial extracts of S. coelicolor and shown to be BldD. The BldD binding site in the sigHp2 promoter was defined by DNase I footprinting. These data show that expression of sigmaH is subject to temporal and spatial regulation during colony development, that this tissue-specific regulation is mediated directly by the developmental transcription factor BldD and suggest that stress and developmental programmes may be intimately connected in Streptomyces morphogenesis.
Collapse
Affiliation(s)
- G H Kelemen
- Department of Molecular Microbiology, John Innes Centre, Colney, Norwich NR4 7UH, UK
| | | | | | | | | | | |
Collapse
|
11
|
Bock JV, Battershell T, Wiggington J, John TR, Johnson JD. Frankia sequences exhibiting RNA polymerase promoter activity. MICROBIOLOGY (READING, ENGLAND) 2001; 147:499-506. [PMID: 11158367 DOI: 10.1099/00221287-147-2-499] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Frankia are Gram-positive, filamentous bacteria capable of fixing atmospheric dinitrogen either in the free-living state or in symbiosis with a variety of woody plants. Only a few Frankia genes have been sequenced and gene expression is not well characterized. To isolate a segment of Frankia DNA that functions as an RNA polymerase promoter, fragments of Frankia strain ArI5 genomic DNA were cloned upstream of a promoterless, Vibrio harveyi luxAB cassette. Constructs were screened for luminescence in E. coli and positive clones assayed for in vitro transcription activity with a partially purified Frankia RNA polymerase extract. Primer extension analysis of in vitro transcripts produced from one clone, GLO7, identified two major transcription start sites, TSP-1 and TSP-2, 52 bp apart. Deletion analysis then localized sequences essential for promoter activity. The upstream promoter region, GLO7p1, contains sequences resembling the -35 element of a Streptomyces promoter and the -35 and -10 elements of the canonical E. coli promoter. Also within this region are two pentamers identical to sequences near the 5' end of the Frankia strain CpI1 glutamine synthetase gene. The second promoter, GLO7p2, contains a putative NtrC binding site at -145 and a possible sigma(N)-RNA polymerase recognition sequence at -14 suggesting that GLO7p2 may be a nitrogen-regulated promoter. An in vivo transcript representing an ORF of 498 aa starting 64 bp downstream of the distal transcription start, TSP-1, was detected by RT-PCR. This supports the conclusion that this DNA fragment has promoter activity in vivo as well as in vitro.
Collapse
Affiliation(s)
- Joyce V Bock
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA1
| | - Ty Battershell
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA1
| | - James Wiggington
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA1
| | - Theodore R John
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA1
| | - Jerry D Johnson
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, USA1
| |
Collapse
|
12
|
Cho YH, Lee EJ, Roe JH. A developmentally regulated catalase required for proper differentiation and osmoprotection of Streptomyces coelicolor. Mol Microbiol 2000; 35:150-60. [PMID: 10632885 DOI: 10.1046/j.1365-2958.2000.01685.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Streptomyces coelicolor produces at least three catalases, the expression of which varies under different conditions. We characterized a gene (catB) for developmentally controlled catalase of 779 amino acids (83408 Da), homologous to KatE of Escherichia coli and Bacillus subtilis. Expression of the catB gene increased at the stationary phase in liquid culture and after the onset of differentiation on solid culture. It was also increased by osmotic treatments. Transcription was initiated from a promoter (catBp), whose sequence (ATGCCTCG-N13-GGGTAC) resembled promoters recognized by sigmaB of B. subtilis. CatB protein underwent proteolytic cleavage of its N-terminal 95 amino acids and was secreted to the medium when cells sporulated. Disruption of the catB gene caused impairment in the formation of aerial mycelium and reduction in the synthesis of undecylprodigiosin. On the contrary, hyperproduction of actinorhodin was observed in accordance with the increase in actII-ORF4 transcription. In addition, catB mutant became hypersensitive to osmotic stresses. These results suggest that regulated synthesis of CatB protein is necessary to ensure proper differentiation as well as to protect S. coelicolor cells against osmotic stresses.
Collapse
Affiliation(s)
- Y H Cho
- Department of Microbiology, College of Natural Sciences and Research Center for Molecular Microbiology, Seoul National University, Seoul 151-742, Korea
| | | | | |
Collapse
|
13
|
Hopwood DA. Forty years of genetics with Streptomyces: from in vivo through in vitro to in silico. MICROBIOLOGY (READING, ENGLAND) 1999; 145 ( Pt 9):2183-2202. [PMID: 10517572 DOI: 10.1099/00221287-145-9-2183] [Citation(s) in RCA: 205] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- David A Hopwood
- John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK1
| |
Collapse
|
14
|
McDowall KJ, Thamchaipenet A, Hunter IS. Phosphate control of oxytetracycline production by Streptomyces rimosus is at the level of transcription from promoters overlapped by tandem repeats similar to those of the DNA-binding sites of the OmpR family. J Bacteriol 1999; 181:3025-32. [PMID: 10322002 PMCID: PMC93756 DOI: 10.1128/jb.181.10.3025-3032.1999] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1998] [Accepted: 02/22/1999] [Indexed: 11/20/2022] Open
Abstract
Physiological studies have shown that Streptomyces rimosus produces the polyketide antibiotic oxytetracycline abundantly when its mycelial growth is limited by phosphate starvation. We show here that transcripts originating from the promoter for one of the biosynthetic genes, otcC (encoding anhydrotetracycline oxygenase), and from a promoter for the divergent otcX genes peak in abundance at the onset of antibiotic production induced by phosphate starvation, indicating that the synthesis of oxytetracycline is controlled, at least in part, at the level of transcription. Furthermore, analysis of the sequences of the promoters for otcC, otcX, and the polyketide synthase (otcY) genes revealed tandem repeats having significant similarity to the DNA-binding sites of ActII-Orf4 and DnrI, which are Streptomyces antibiotic regulatory proteins (SARPs) related to the OmpR family of transcription activators. Together, the above results suggest that oxytetracycline production by S. rimosus requires a SARP-like transcription factor that is either produced or activated or both under conditions of low phosphate concentrations. We also provide evidence consistent with the otrA resistance gene being cotranscribed with otcC as part of a polycistronic message, suggesting a simple mechanism of coordinate regulation which ensures that resistance to the antibiotic increases in proportion to production.
Collapse
Affiliation(s)
- K J McDowall
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | | | | |
Collapse
|
15
|
Mulder MA, Zappe H, Steyn LM. Mycobacterial promoters. TUBERCLE AND LUNG DISEASE : THE OFFICIAL JOURNAL OF THE INTERNATIONAL UNION AGAINST TUBERCULOSIS AND LUNG DISEASE 1999; 78:211-23. [PMID: 10209675 DOI: 10.1016/s0962-8479(97)90001-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- M A Mulder
- Department of Medical Microbiology, University of Cape Town, South Africa
| | | | | |
Collapse
|
16
|
Davagnino J, Springer AL, Lidstrom ME. An RNA polymerase preparation from Methylobacterium extorquens AM1 capable of transcribing from a methylotrophic promoter. MICROBIOLOGY (READING, ENGLAND) 1998; 144 ( Pt 1):177-182. [PMID: 9467910 DOI: 10.1099/00221287-144-1-177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
RNA polymerase (RNAP) was purified from Methylobacterium extorquens AM1 cells grown on methanol or on succinate. The beta, beta', alpha and omega subunits were approximately the same size as those of Escherichia coli, and the identity of the omega subunit was confirmed by N-terminal sequence analysis. N-terminal sequence analysis suggested that two other polypeptides in the purified RNAP preparation might be sigma factors, a 40 kDa polypeptide that shared identity with sigma 32 homologues, and a 97 kDa polypeptide that shared identity with sigma 70 homologues in other bacteria. The 97 kDa polypeptide did not cross-react with antibody to E. coli sigma 70. The same complement of putative sigma factors was found in RNAP purified from M. extorquens AM1 grown on succinate and those grown on methanol, indicating that no major methanol-inducible sigma factor is present in this strain. Run-off assays showed that the purified RNAP was capable of initiating transcription specifically at the transcriptional start site of a methylotrophic gene, mxaF, which encodes the large subunit of methanol dehydrogenase and is found only in methylotrophic bacteria.
Collapse
Affiliation(s)
- Juan Davagnino
- Department of Chemical Engineering, Box 357242, University of Washington, Seattle, WA 98195-1750, USA
| | - Amy L Springer
- Department of Chemical Engineering, Box 357242, University of Washington, Seattle, WA 98195-1750, USA
| | - Mary E Lidstrom
- Box 351750 and Department of Microbiology, Box 357242, University of Washington, Seattle, WA 98195-1750, USA
- Department of Chemical Engineering, Box 357242, University of Washington, Seattle, WA 98195-1750, USA
| |
Collapse
|
17
|
|
18
|
Ni X, Westpheling J. Direct repeat sequences in the Streptomyces chitinase-63 promoter direct both glucose repression and chitin induction. Proc Natl Acad Sci U S A 1997; 94:13116-21. [PMID: 9371809 PMCID: PMC24272 DOI: 10.1073/pnas.94.24.13116] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The chi63 promoter directs glucose-sensitive, chitin-dependent transcription of a gene involved in the utilization of chitin as carbon source. Analysis of 5' and 3' deletions of the promoter region revealed that a 350-bp segment is sufficient for wild-type levels of expression and regulation. The analysis of single base changes throughout the promoter region, introduced by random and site-directed mutagenesis, identified several sequences to be important for activity and regulation. Single base changes at -10, -12, -32, -33, -35, and -37 upstream of the transcription start site resulted in loss of activity from the promoter, suggesting that bases in these positions are important for RNA polymerase interaction. The sequences centered around -10 (TATTCT) and -35 (TTGACC) in this promoter are, in fact, prototypical of eubacterial promoters. Overlapping the RNA polymerase binding site is a perfect 12-bp direct repeat sequence. Some base changes within this direct repeat resulted in constitutive expression, suggesting that this sequence is an operator for negative regulation. Other base changes resulted in loss of glucose repression while retaining the requirement for chitin induction, suggesting that this sequence is also involved in glucose repression. The fact that cis-acting mutations resulted in glucose resistance but not inducer independence rules out the possibility that glucose repression acts exclusively by inducer exclusion. The fact that mutations that affect glucose repression and chitin induction fall within the same direct repeat sequence module suggests that the direct repeat sequence facilitates both chitin induction and glucose repression.
Collapse
Affiliation(s)
- X Ni
- Genetics Department, University of Georgia, Athens 30602, USA
| | | |
Collapse
|
19
|
Babcock MJ, Buttner MJ, Keler CH, Clarke BR, Morris RA, Lewis CG, Brawner ME. Characterization of the rpoC gene of Streptomyces coelicolor A3(2) and its use to develop a simple and rapid method for the purification of RNA polymerase. Gene X 1997; 196:31-42. [PMID: 9322738 DOI: 10.1016/s0378-1119(97)00179-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The Streptomyces coelicolor rpoC gene, that encodes the beta' subunit of RNA polymerase, was isolated using the Escherichia coli rpoC gene as a hybridization probe. Comparison of the predicted amino acid sequence of the S. coelicolor beta' subunit to those characterized from other bacteria revealed three distinct subfamilies of beta' subunits, one of which consists of the S. coelicolor subunit and those from Mycobacterium leprae and Mycoplasma genitalium. Using site-directed mutagenesis, the carboxy terminus of the S. coelicolor beta' subunit was modified to contain six histidine residues. The histidine-tagged gene, rpoCHIS, was used to replace the wild-type allele in the chromosome of S. coelicolor and S. lividans. These strains were unaffected in growth and sporulation, demonstrating that the histidine-tagged RNA polymerase was competent to carry out all essential in-vivo functions. During a 1-day procedure, highly purified RNA polymerase was obtained by nickel-NTA agarose affinity chromatography followed by heparin-sepharose chromatography. Using in-vitro run-off transcription assays, the affinity purified RNA polymerase was shown to initiate transcription correctly from the S. lividans galP1 and galP2 promoters, and the Bacillus subtilus veg and ctc promoters. An extension of this procedure yielded highly-purified core RNA polymerase. To facilitate introduction of the rpoCHIS allele into other genetic backgrounds, a mutation in the adjacent gene, rpoB (rifA), conferring rifampin-resistance, was isolated in S. coelicolor to provide a genetic marker to follow transfer of the rpoCHIS allele. The use of this affinity chromatography procedure, in combination with the ability to introduce the rpoCHIS allele into different Streptomyces strains by transformation, will greatly facilitate the in-vitro analysis of transcription in members of this genus.
Collapse
Affiliation(s)
- M J Babcock
- Department of Gene Expression Sciences, SmithKline Beecham, King of Prussia, PA 19406, USA
| | | | | | | | | | | | | |
Collapse
|
20
|
Kang JG, Hahn MY, Ishihama A, Roe JH. Identification of sigma factors for growth phase-related promoter selectivity of RNA polymerases from Streptomyces coelicolor A3(2). Nucleic Acids Res 1997; 25:2566-73. [PMID: 9185565 PMCID: PMC146787 DOI: 10.1093/nar/25.13.2566] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We examined the promoter selectivity of RNA polymerase (RNAP) from Streptomyces coelicolor at two growth phases by in vitro transcription. Distinct sets of promoters were preferentially recognized by either exponential or stationary phase RNAP. No change in molecular weight or net charge of the core subunits was observed, suggesting that the associated specificity factors determined phase-specific promoter selectivity of the holoenzyme. Five different specificity factors and their cognate promoters were identified by in vitro holoenzyme reconstitution and transcription assays. sigma66 (sigma hrdB) and sigma46 (sigma hrdD) recognized promoters (rrnD p2 and dagA p4 for sigma66, actII-orf4 p and whiB p2 for sigma46) preferentially transcribed by the exponential phase RNAP. sigma52 recognized promoters (dagA p3 and actIII px1) preferentially transcribed by the stationary phase RNAP. Sigma28 (sigma sigE) recognized promoters (hrdD p1, whiB p1 and dagA p2) transcribed equally by both RNAPs. A novel 31 kDa specificity factor recognized actIII px2, glnR p2 and hrdD p2 promoters preferentially transcribed by the stationary phase RNAP. This factor was isolated from the stationary phase RNAP and reconstituted holoenzyme in vitro as a sigma factor. The N-terminal sequence suggests that it is a novel factor. By examining phase-specific promoter recognition pattern we can predict that holoenzyme Esigma52 and Esigma31 activities are higher in the stationary phase, whereas Esigma66 and Esigma46activities are higher in the exponential phase. Possible promoter sequences recognized by some of these sigma factors were suggested.
Collapse
Affiliation(s)
- J G Kang
- Department of Microbiology, College of Natural Sciences, and Research Center for Molecular Microbiology, Seoul National University, Seoul 151-742, Korea
| | | | | | | |
Collapse
|
21
|
Labes G, Bibb M, Wohlleben W. Isolation and characterization of a strong promoter element from the Streptomyces ghanaensis phage I19 using the gentamicin resistance gene (aacC1) of Tn 1696 as reporter. MICROBIOLOGY (READING, ENGLAND) 1997; 143 ( Pt 5):1503-1512. [PMID: 9168600 DOI: 10.1099/00221287-143-5-1503] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A promoter-probe shuttle plasmid (pGL7011) containing the promoterless aminoglycoside-O-acetyltransferase I gene (aacC1) of Tn1696 was used to isolate DNA fragments from Streptomyces ghanaensis phage I19 that possessed promoter activity in Streptomyces lividans TK23. Analysis of gentamicin (Gm) resistance levels in Escherichia coli and in S. lividans TK23, and of aacC1 mRNA levels in S. lividans, identified a fragment (F14) that exhibited a high level of promoter activity in both species. Subsequent analysis revealed that the promoter activity of SF14 (a subcloned fragment of F14) was about twice that of ermEp*, one of the strongest characterized actinomycete promoters. SF14 contained two tandemly arranged promoters, 14-Ip and p14-IIp, with overlapping and adjacent -10 and -35 regions, respectively. Both promoters appear to be recognized with different efficiencies by the major RNA polymerase holoenzyme (E sigma hrdB) of Streptomyces coelicolor A3(2).
Collapse
Affiliation(s)
- Gabriele Labes
- Lehrstuhl für Genetik, Universität Bielefeld, Universitätsstr. 25, 33501 Bielefeld, Germany
| | - Mervyn Bibb
- Lehrstuhl für Genetik, Universität Bielefeld, Universitätsstr. 25, 33501 Bielefeld, Germany
| | - Wolfgang Wohlleben
- Lehrstuhl für Genetik, Universität Bielefeld, Universitätsstr. 25, 33501 Bielefeld, Germany
| |
Collapse
|
22
|
Brawner ME, Mattern SG, Babcock MJ, Westpheling J. The Streptomyces galP1 promoter has a novel RNA polymerase recognition sequence and is transcribed by a new form of RNA polymerase in vitro. J Bacteriol 1997; 179:3222-31. [PMID: 9150217 PMCID: PMC179100 DOI: 10.1128/jb.179.10.3222-3231.1997] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We report the identification of DNA sequences that determine the activity of the Streptomyces galP1 promoter and a new form of RNA polymerase holoenzyme that recognizes these sequences in vitro. Base substitutions were introduced throughout the galP1 promoter region, and bases at positions -34, -36, and -11 with respect to the transcription start site were shown to be required for promoter function. These bases correspond in their positions to regions known to be important for RNA polymerase binding in several classes of eubacterial promoters, but the sequences themselves are not similar to those previously described. The -35 region of the galP1 promoter consists of six G residues, and base changes in this G hexamer had a dramatic effect on promoter activity. By using galP1-containing DNA template, a new RNA polymerase activity was purified from Streptomyces. Holoenzyme reconstitution experiments identified a new sigma factor that directs galP1 transcription in vitro. DNase I protection experiments identified a binding site for this new holoenzyme immediately upstream of the galP1 transcription start site.
Collapse
Affiliation(s)
- M E Brawner
- Gene Expression Sciences, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406, USA
| | | | | | | |
Collapse
|
23
|
Kojic M, Topisirovic L, Vasiljevic B. Translational autoregulation of the sgm gene from Micromonospora zionensis. J Bacteriol 1996; 178:5493-8. [PMID: 8808941 PMCID: PMC178373 DOI: 10.1128/jb.178.18.5493-5498.1996] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The sisomicin-gentamicin resistance methylase gene (sgm) from Micromonospora zionensis (the producer of antibiotic G-52 [6-N-methyl-sisomicin]) encodes an enzyme that modifies 16S rRNA and thereby confers resistance to 4,6-disubstituted deoxystreptamine aminoglycosides. Here, we report that this gene is regulated on the translational level. The Escherichia coli lacZ gene and operon fusion system was used, and it was shown that an extra copy of the sgm gene decreases the activity of the fusion protein. These results suggested that expression of the sgm gene is regulated by the translational autorepression because of binding of the methylase to its own mRNA. It was shown by computer analysis that the same hexanucleotide (CCGCCC) is present 14 bp before the ribosome-binding site and in the C-1400 region of 16S rRNA, i.e., the region in which most of the aminoglycosides act. A deletion that removes the hexanucleotide before the gene fusion is not prone to negative autoregulation. This mode of regulation of the sgm gene ensures that enough methylase molecules protect the cell from the action of its own antibiotic. On the other hand, if all of the ribosomes are modified, Sgm methylase binds to its own mRNA in an autorepressive manner.
Collapse
Affiliation(s)
- M Kojic
- Institute of Molecular Genetics and Genetic Engineering, Belgrade, Yugoslavia
| | | | | |
Collapse
|
24
|
Bashyam MD, Kaushal D, Dasgupta SK, Tyagi AK. A study of mycobacterial transcriptional apparatus: identification of novel features in promoter elements. J Bacteriol 1996; 178:4847-53. [PMID: 8759847 PMCID: PMC178266 DOI: 10.1128/jb.178.16.4847-4853.1996] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Our earlier studies on transcriptional signals of mycobacteria had revealed that (i) strong promoters occur less frequently in the slowly growing pathogen Mycobacterium tuberculosis H37Rv than in the fast-growing saprophyte M. smegmatis and (ii) mycobacterial promoters function poorly in Escherichia coli. We now present evidence that RNA polymerases of M. smegmatis, M. tuberculosis, and M. bovis BCG recognize promoter elements with comparable efficiencies. Analysis of these randomly isolated mycobacterial promoters by DNA sequencing, primer extension, and deletion experiments revealed that their -10 regions are highly similar to those of E. coli promoters, in contrast to their -35 regions, which can tolerate a greater variety of sequences, owing presumably to the presence of multiple sigma factors with different or overlapping specificities for -35 regions, as reported earlier for the Streptomyces promoters. A comparison of the -10 and -35 binding domains of MysA, HrdB, and RpoD (the principal sigma factors of M. smegmatis, Streptomyces aureofaciens, and E. coli, respectively) showed that all three sigma factors have nearly identical -10 binding domains. However, the -35 binding domains of the principal mycobacterial and streptomycete sigma factors, although nearly identical to each other, are vastly different from the corresponding region of the sigma factor of E. coli. Thus, the transcriptional signals of mycobacteria have features in common with Streptomyces promoters but differ from those of E. coli because of major differences in the -35 regions of the promoters and the corresponding binding domain in the sigma factor.
Collapse
Affiliation(s)
- M D Bashyam
- Department of Biochemistry, University of Delhi South Campus, India
| | | | | | | |
Collapse
|
25
|
Bibb M. 1995 Colworth Prize Lecture. The regulation of antibiotic production in Streptomyces coelicolor A3(2). MICROBIOLOGY (READING, ENGLAND) 1996; 142 ( Pt 6):1335-1344. [PMID: 8704973 DOI: 10.1099/13500872-142-6-1335] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Mervyn Bibb
- Department of Genetics, John Innes CentreNorwich Research Park, Colney, Norwich NR4 7UH,UK
| |
Collapse
|
26
|
Fujita M, Hanaura Y, Amemura A. Analysis of the rpoD gene encoding the principal sigma factor of Pseudomonas putida. Gene 1995; 167:93-8. [PMID: 8566819 DOI: 10.1016/0378-1119(95)00675-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The gene (rpoD) encoding the principal sigma factor of Pseudomonas putida (Pp) was cloned and sequenced. The amino-acid sequence deduced from the nucleotide sequence of rpoD contained sequences with significant similarity to the conserved region of the principal sigma factors. In vivo transcriptional analyses revealed that the Pp rpoD is transcribed as a monocistronic mRNA of 2.1 kb and that the transcription of rpoD is under control of the heat-shock (HS) response. The transcription start point (tsp) of the gene was determined and found to be different depending on either normal growth (at 30 degrees C) or HS (at 42 degrees C) conditions. The possible promoter sequences for the principal (sigma 70) and the HS RNA polymerase of Pseudomonas were located in the upstream region of the tsp.
Collapse
Affiliation(s)
- M Fujita
- Radiosotope Center, National Institute of Genetics, Shizuoka, Japan
| | | | | |
Collapse
|
27
|
Bourn WR, Babb B. Computer assisted identification and classification of streptomycete promoters. Nucleic Acids Res 1995; 23:3696-703. [PMID: 7478999 PMCID: PMC307268 DOI: 10.1093/nar/23.18.3696] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Short sequences that were over represented in a database of Streptomyces promoter region sequences were identified. These sequences and others that were selected on the basis of the characteristics of known promoters, were tested to determine if they were found predominantly at particular distances from the transcription start site. In several cases obvious clusters were recorded. This has allowed the objective identification of potential promoter core sequences. In some cases these may define novel promoter classes. 150 Streptomyces promoters have been listed and grouped on this basis. A new and extended consensus sequence for the Streptomyces E.coli sigma 70-like promoters was determined. It showed differences from that of E.coli, both in sequence and in the spacing between the -35 and -10 regions.
Collapse
Affiliation(s)
- W R Bourn
- Department of Microbiology, University of Cape Town, Rondebosch, South Africa
| | | |
Collapse
|
28
|
Im H. The sapA promoter from Streptomyces coelicolor requires activation sites and initiator-like sequences but No -10 or -35 sequences. J Bacteriol 1995; 177:4601-8. [PMID: 7642485 PMCID: PMC177223 DOI: 10.1128/jb.177.16.4601-4608.1995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The Streptomyces coelicolor sapA gene encodes a spore coat protein. The sapA promoter is regulated developmentally, with maximal expression occurring in aerial hyphae at a late stage of colonial development. The DNA sequences upstream from the transcription start point do not appear to fall into a previously described promoter class. One (or more) putative activation site, required for full activity, is eliminated when 5' deletions extend to between -178 and -72 bases upstream from the transcription start point. In addition, a downstream activation site is destroyed by removing sequences between positions +40 and +120, relative to the transcription start point, in the absence of an intact upstream region. However, temporal regulation of transcription initiation over the course of the life cycle is maintained faithfully in the absence of these elements, even in the smallest 18-bp sapAp fragment containing sequences from positions -8 to +10. Site-specific mutations around the transcriptional start points shift the timing of sapA expression to an earlier stage in the developmental cycle. These results sugges that a novel mechanism may be involved in Streptomyces late gene expression.
Collapse
Affiliation(s)
- H Im
- Department of Microbiology, University of Texas, Austin 78712, USA
| |
Collapse
|
29
|
Marcos AT, Gutiérrez S, Díez B, Fernández FJ, Oguiza JA, Martín JF. Three genes hrdB, hrdD and hrdT of Streptomyces griseus IMRU 3570, encoding sigma factor-like proteins, are differentially expressed under specific nutritional conditions. Gene 1995; 153:41-8. [PMID: 7883183 DOI: 10.1016/0378-1119(94)00759-l] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Three genes (hrd) homologous to the rpoD gene of Escherichia coli, that encode sigma factor-like proteins, have been cloned from DNA of the candicidin-producing strain Streptomyces griseus IMRU 3570. They are located in different regions of the chromosome. Sequence analysis showed that the first one is analogous to the hrdB gene of S. coelicolor. The second showed high similarity to the hrdD gene of S. coelicolor and S. aureofaciens and is linked, as in S. coelicolor, to a N-acetyltransferase-encoding gene (nat) distantly related to the pat and bar genes that encode resistance to bialafos. The third showed no close homology with other known hrd genes from actinomycetes and has been named hrdT. Functional domains in the three S. griseus Hrd proteins are highly conserved in relation to those of the sigma 70 protein family. Northern analysis showed that hrdB is expressed as a 1.9-kb transcript during active growth in phosphate-rich medium, but it is less efficiently transcribed under sporulation conditions (phosphate-starved) or after a heat-shock treatment. Two other shorter transcripts of 1.2 and 0.7 kb were also detected with the same probe. The hrdD gene is transcribed as a single 1.1-kb transcript under sporulation conditions following nutritional shiftdown and, to a lower extent, during growth conditions in phosphate-rich medium. The hrdT gene is weakly transcribed (1.5-kb RNA) under all conditions tested. The hrd-encoded sigma factors probably recognize actinomycetes promoters (SEP type) with E. coli-like consensus sequences.
Collapse
Affiliation(s)
- A T Marcos
- Department of Ecology, Genetics and Microbiology, Faculty of Biology, University of León, Spain
| | | | | | | | | | | |
Collapse
|
30
|
Krausová M, Klégr M, Spízek J. Isolation of DNA-dependent RNA polymerase from the thermophilic actinomycete Thermomonospora curvata. Folia Microbiol (Praha) 1994; 39:7-12. [PMID: 8181783 DOI: 10.1007/bf02814521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
DNA-Dependent RNA polymerase (EC 2.7.7.6) was isolated from Thermomonospora curvata. The purification steps included precipitation with Polymin P, elution of the precipitate with 0.3 mol/L KCl, precipitation with ammonium sulfate, affinity chromatography on heparin-agarose and molecular filtration on Biogel A 1.5 m.
Collapse
Affiliation(s)
- M Krausová
- Institute of Microbiology, Academy of Sciences of Czech Republic, Prague
| | | | | |
Collapse
|
31
|
Ward JM, Hodgson JE. The biosynthetic genes for clavulanic acid and cephamycin production occur as a 'super-cluster' in three Streptomyces. FEMS Microbiol Lett 1993; 110:239-42. [PMID: 8349096 DOI: 10.1111/j.1574-6968.1993.tb06326.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The cosmid cloning vector pHC79 has been used to clone fragments of chromosomal DNA from the Streptomyces: S. clavuligerus, S. jumonjinensis and S. katsurahamanus. These strains all produce both the beta-lactam antibiotic, cephamycin and the beta-lactamase inhibitor, clavulanic acid. Although structurally related these two beta-lactams are known to be derived from different biosynthetic precursors. Hybridisation studies and restriction mapping have shown that the gene clusters encoding the two biosynthetic pathways are chromosomally adjacent in these strains, thus creating a 'super-cluster' of genes involved in both the production and enhancement of activity of a beta-lactam antibiotic.
Collapse
Affiliation(s)
- J M Ward
- SmithKline Beecham Pharmaceuticals, Brockham Park Research Centre, Betchworth, Surrey, UK
| | | |
Collapse
|
32
|
Parro V, Mellado RP. Heterologous recognition in vivo of promoter sequences from the Streptomyces coelicolor dagA gene. FEMS Microbiol Lett 1993; 106:347-56. [PMID: 7681021 DOI: 10.1111/j.1574-6968.1993.tb05987.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The Streptomyces coelicolor dagA gene that codes for an extracellular agarase was cloned in the closely related bacterium S. lividans and transferred to the distantly related low G+C Gram-positive bacterium Bacillus subtilis and to the far more distantly related Gram-negative bacterium Escherichia coli. S1 nuclease mapping experiments identified a putative fifth promoter from which transcription of the dagA gene can take place, and accurately mapped the transcription termination site. The transcription terminator was specific for the Streptomyces strains and could terminate transcription initiated by promoters other than those of dagA. The agarase gene is efficiently transcribed in B. subtilis and E. coli, although pulse-chase experiments failed to detect the synthesis of agarase in these two bacteria.
Collapse
Affiliation(s)
- V Parro
- Centro Nacional de Biotecnología, Universidad Autónoma, Madrid, Spain
| | | |
Collapse
|
33
|
Cloning of a Microbispora bispora cellobiohydrolase gene in Streptomyces lividans. Appl Microbiol Biotechnol 1993. [DOI: 10.1007/bf00182802] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
34
|
Newlands JT, Gaal T, Mecsas J, Gourse RL. Transcription of the Escherichia coli rrnB P1 promoter by the heat shock RNA polymerase (E sigma 32) in vitro. J Bacteriol 1993; 175:661-8. [PMID: 8423142 PMCID: PMC196203 DOI: 10.1128/jb.175.3.661-668.1993] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The P1 promoters of the seven Escherichia coli rRNA operons contain recognition sequences for the RNA polymerase (RNAP) holoenzyme containing sigma 70 (E sigma 70), which has been shown to interact with and initiate transcription from rrn P1 promoters in vivo and in vitro. The rrn P1 promoters also contain putative recognition elements for E sigma 32, the RNAP holoenzyme responsible for the transcription of heat shock genes. Using in vitro transcription assays with purified RNAP holoenzyme, we show that E sigma 32 is able to transcribe from the rrnB P1 promoter. Antibodies specific to sigma 70 eliminate transcription of rrnB P1 by E sigma 70 but have no effect on E sigma 32-directed transcription. Physical characterization of the E sigma 32-rrnB P1 complex shows that there are differences in the interactions made by E sigma 70 and E sigma 32 with the promoter. E sigma 32 responds to both Fis-mediated and factor-independent upstream activation, two systems shown previously to stimulate rrnB P1 transcription by E sigma 70. We find that E sigma 32 is not required for two major control systems known to regulate rRNA transcription initiation at normal temperatures in vivo, stringent control and growth rate-dependent control. On the basis of the well-characterized role of E sigma 32 in transcription from heat shock promoters in vivo, we suggest that E sigma 32-directed transcription of rRNA promoters might play a role in ribosome synthesis at high temperatures.
Collapse
Affiliation(s)
- J T Newlands
- Department of Bacteriology, University of Wisconsin, Madison 53706
| | | | | | | |
Collapse
|
35
|
Yeung MK. Complete nucleotide sequence of the Actinomyces viscosus T14V sialidase gene: presence of a conserved repeating sequence among strains of Actinomyces spp. Infect Immun 1993; 61:109-16. [PMID: 8418033 PMCID: PMC302694 DOI: 10.1128/iai.61.1.109-116.1993] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The nucleotide sequence of the Actinomyces viscosus T14V sialidase gene (nanH) and flanking regions was determined. An open reading frame of 2,703 nucleotides that encodes a predominately hydrophobic protein of 901 amino acids (M(r), 92,871) was identified. The amino acid sequence at the amino terminus of the predicted protein exhibited properties characteristic of a typical leader peptide. Five 12-amino-acid units that shared between 33 and 67% sequence identity were noted within the central domain of the protein. Each unit contained the sequence Ser-X-Asp-X-Gly-X-Thr-Trp, which is conserved among other bacterial and trypanosoma sp. sialidases. Thus, the A. viscosus T14V nanH gene and the other prokaryotic and eukaryotic sialidase genes evolved from a common ancestor. Southern hybridization analyses under conditions of high stringency revealed the existence of DNA sequences homologous to A. viscosus T14V nanH in the genomes of 18 strains of five Actinomyces species that expressed various levels of sialidase activity. The data demonstrate that the sialidase genes from divergent groups of Actinomyces spp. are highly conserved.
Collapse
Affiliation(s)
- M K Yeung
- Department of Pediatric Dentistry, University of Texas Health Science Center, San Antonio 78284
| |
Collapse
|
36
|
Kojic M, Topisirovic L, Vasiljevic B. Cloning and characterization of an aminoglycoside resistance determinant from Micromonospora zionensis. J Bacteriol 1992; 174:7868-72. [PMID: 1447159 PMCID: PMC207509 DOI: 10.1128/jb.174.23.7868-7872.1992] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The sisomicin-gentamicin resistance methylase (sgm) gene was isolated from Micromonospora zionensis and cloned in Streptomyces lividans. The sgm gene was expressed in Micromonospora melanosporea, where its own promoter was active, and also in Escherichia coli under the control of the lacZ promoter. The complete nucleotide sequence of 1,122 bp and a transcription start point were determined. The sequence contains an open reading frame that encodes a polypeptide of 274 amino acids. The methylation of 30S ribosomal subunits by Sgm methylase accounts adequately for all known resistance characteristics of M. zionensis, but expression of high-level resistance to hygromycin B is background dependent. A comparison of the amino acid sequence of the predicted Sgm protein with the deduced amino acid sequences for the 16S rRNA methylases showed extensive similarity of Grm and significant similarity to KgmB but not to KamB methylase.
Collapse
Affiliation(s)
- M Kojic
- Institute of Molecular Genetics and Genetic Engineering, Belgrade, Yugoslavia
| | | | | |
Collapse
|
37
|
Forsman M, Granström M. Mutagenic analysis of the promoter of the Streptomyces fradiae beta-lactamase-encoding gene. Gene X 1992; 121:87-94. [PMID: 1385267 DOI: 10.1016/0378-1119(92)90165-l] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The Streptomyces fradiae beta-lactamase promoter (PblaF) was sequenced and characterized by promoter probing, primer extension, and exonuclease III-mediated deletions. The transcription start point (tsp) was the same in both S. lividans and S. fradiae. Oligodeoxyribonucleotide-directed random mutations and site-specific mutations were introduced in the promoter region. The effects of these mutations on transcription were assayed by an RNA colony hybridization method. This analysis identified cis-acting sequence determinants located similarly to the -10 and -35 regions of a typical Escherichia coli promoter. Also, a change in the distance between these regions from 19 to 17 bp drastically reduced promoter activity. PblaF was shown not to be recognized by sigma-whiG or by sigma-hrdA, hrdC, or hrdD. Sequence alignment of PblaF to sigma factor-classified Streptomyces promoters revealed little homology. Thus, PblaF is probably recognized by an as yet unidentified sigma factor.
Collapse
Affiliation(s)
- M Forsman
- Department of Microbiology, National Defence Research Establishment, Umeå, Sweden
| | | |
Collapse
|
38
|
Abstract
We demonstrated previously that the promoters P1a, P1b, and P1c are very closely spaced and are coordinately turned on during stationary phase in Micromonospora echinospora. To determine the nucleotides important for promoter recognition, we characterized mutations that were defective in transcription from the P1b start site, using Streptomyces lividans as the host. Two mutations upstream of the start site resulted in a drastic loss of promoter activity, while two mutations downstream of the start site resulted in a moderate loss of activity. These mutations suggest an unexpected relationship between promoters P1b and P1c. Three of the mutations that caused diminished transcription from promoter P1b simultaneously resulted in an increase in transcription from the P1c promoter initiation site located 15 bp downstream. Despite the proximity and the coordinate regulation of promoters P1b and P1c, they are in competition as transcriptional start sites.
Collapse
Affiliation(s)
- L S Lin
- Department of Microbial Genetics, Lederle Laboratories, Pearl River, New York 10965
| | | |
Collapse
|
39
|
Brown KL, Wood S, Buttner MJ. Isolation and characterization of the major vegetative RNA polymerase of Streptomyces coelicolor A3(2); renaturation of a sigma subunit using GroEL. Mol Microbiol 1992; 6:1133-9. [PMID: 1350315 DOI: 10.1111/j.1365-2958.1992.tb01551.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The promoter region of the agarase gene (dagA) of Streptomyces coelicolor A3(2) is complex; it consists of four distinct promoters with different -10 and -35 regions. We report the isolation of a form of RNA polymerase that mediates transcription in vitro from the dagAp4 promoter. The core components of this RNA polymerase are associated with a polypeptide of c. 66 kDa; holoenzyme reconstitution experiments show that the 66 kDa polypeptide functions as a sigma factor that directs transcription from the dagAp4 and Bacillus subtilis veg promoters in vitro. Alignment of the DNA sequences of these two promoters shows that they have bases in common in the -10 and -35 regions and that these sequences are similar to those observed for the major RNA polymerases of other bacteria. N-terminal amino acid sequence analysis of the 66 kDa polypeptide revealed it to be the product of the hrdB gene. Previous experiments showed that the predicted amino acid sequence of the hrdB gene product is very similar to the major sigma factors of other bacteria and suggested that disruption of the hrdB gene is lethal. These observations together lead to the conclusion that we have isolated the major RNA polymerase of Streptomyces coelicolor A3(2). We have developed an improved protocol for the renaturation of sigma factors that have been isolated by preparative sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS-PAGE). This method involves renaturing the polypeptide in the presence of the bacterial chaperonin GroEL. We expect this protocol to find general application for renaturation of other polypeptides that have been subjected to SDS-PAGE.
Collapse
Affiliation(s)
- K L Brown
- School of Biological Sciences, University of East Anglia, University Plain, Norwich, UK
| | | | | |
Collapse
|
40
|
Strohl WR. Compilation and analysis of DNA sequences associated with apparent streptomycete promoters. Nucleic Acids Res 1992; 20:961-74. [PMID: 1549509 PMCID: PMC312078 DOI: 10.1093/nar/20.5.961] [Citation(s) in RCA: 390] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The DNA sequences associated with 139 apparent streptomycete transcriptional start sites are compiled and compared. Of these, 29 promoters appeared to belong to a group which are similar to those recognized by eubacterial RNA polymerases containing sigma 70-like subunits. The other 110 putative promoter regions contain a wide diversity of sequences; several of these promoters have obvious sequence similarities in the -10 and/or -35 regions. The apparent Shine-Dalgarno regions of 44 streptomycete genes are also examined and compared. These were found to have a wide range of degree of complementarity to the 3' end of streptomycete 16S rRNA. Eleven streptomycete genes are described and compared in which transcription and translation are proposed to be initiated from the same or nearby nucleotide. An updated consensus sequence for the E sigma 70-like promoters is proposed and a potential group of promoter sequences containing guanine-rich -35 regions also is identified.
Collapse
Affiliation(s)
- W R Strohl
- Department of Microbiology, Ohio State University, Columbus 43210
| |
Collapse
|
41
|
Delic I, Robbins P, Westpheling J. Direct repeat sequences are implicated in the regulation of two Streptomyces chitinase promoters that are subject to carbon catabolite control. Proc Natl Acad Sci U S A 1992; 89:1885-9. [PMID: 1542688 PMCID: PMC48558 DOI: 10.1073/pnas.89.5.1885] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We report the identification and partial characterization of the promoters for two chitinase genes from Streptomyces plicatus. Chitinases are a family of enzymes made by Streptomyces and other soil microbes to digest chitin, an abundant source of carbon and nitrogen in the soil. The promoter regions of two chitinases were defined by using transcriptional fusions to the xylE reporter gene. Transcription was shown to be glucose-sensitive and chitin-dependent. Each promoter contains a putative RNA polymerase binding site with a recognition sequence very similar to that observed in many eubacterial vegetatively expressed genes. In both promoters, a pair of 12-base-pair direct repeat sequences overlap the putative RNA polymerase binding sites. Further analysis of one of the promoters revealed that a single-base change within the direct repeat sequences resulted in glucose-resistant, chitin-independent expression in vivo. In addition, the promoter region that includes the direct repeat sequences was shown to interact with a sequence-specific DNA binding factor in vitro. Similar direct repeat sequences are present in other chitinase genes recently characterized, and we suggest that these repeats may be involved in repression and induction for this entire class of catabolite-controlled genes.
Collapse
Affiliation(s)
- I Delic
- Genetics Department, University of Georgia, Athens 30602
| | | | | |
Collapse
|
42
|
Chang SC, Yang WC, Lee YH. The 16S rRNA gene of Streptomyces lividans TK64 contains internal promoters. ACTA ACUST UNITED AC 1992; 1129:219-22. [PMID: 1370378 DOI: 10.1016/0167-4781(92)90491-h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A 632-bp Sau3AI fragment of Streptomyces lividans TK64 genome was found to confer promoter activity in Streptomyces and Escherichia coli. This fragment showed almost identical sequence (97.8%) to the S. coelicolor 16S rRNA segment encompassing from nucleotide 706 to 1337 region. The transcription start points of this fragment were identified by the primer extension method. Analysis of the nucleotide sequence upstream the transcription start points revealed two putative E. coli-like promoters resided within this fragment. The occurrence of internal promoters active in Streptomyces and E. coli was also confirmed in the 16S rRNA gene of rrnE operon from TK64.
Collapse
Affiliation(s)
- S C Chang
- Institute of Biochemistry, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China
| | | | | |
Collapse
|
43
|
Petrich AK, Wu X, Roy KL, Jensen SE. Transcriptional analysis of the isopenicillin N synthase-encoding gene of Streptomyces clavuligerus. Gene X 1992; 111:77-84. [PMID: 1547956 DOI: 10.1016/0378-1119(92)90605-o] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The gene (pcbC) encoding isopenicillin N synthase of Streptomyces clavuligerus is separated from an upstream open reading frame (ORF) by a 31-bp intergenic region. Inspection of the sequence of this intergenic region did not identify a promoter sequence. The promoter probe plasmid, pIJ4083, which contains the promoter-less catechol-2,3-dioxygenase (C23O)-encoding gene (xylE) as a reporter gene, was used to analyze the sequence upstream from the pcbC gene for promoter activity. Introduction of an SphI site at the start codon of pcbC by site-directed mutagenesis allowed the cloning of a 335-bp fragment (-334 to +1 in relation to the pcbC start codon) immediately upstream from xylE in pIJ4083. C23O activity was detected in both Streptomyces lividans and S. clavuligerus cultures that contained the upstream fragment, suggesting the presence of a promoter sequence. Northern analysis of total RNA extracted from S. clavuligerus identified a monocistronic 1.2-kb transcript hybridizing to a pcbC-specific probe. When RNA was isolated at various times during growth in liquid culture, the presence of a transcript was first detected during stationary phase. Analysis of the pcbC transcript by primer extension located the transcription start point to a C residue within the upstream ORF, 91 bp upstream from the pcbC start codon.
Collapse
Affiliation(s)
- A K Petrich
- Department of Microbiology, University of Alberta, Edmonton, Canada
| | | | | | | |
Collapse
|
44
|
Salauze D, Davies J. Transcriptional mapping of the promoter of the aminoglycoside acetyltransferase gene (aacC9) of neomycin-producing Micromonospora chalcea. Res Microbiol 1992; 143:133-8. [PMID: 1410789 DOI: 10.1016/0923-2508(92)90002-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have studied the promoter of the gene encoding aminoglycoside acetyltransferase (aacC9) in neomycin-producing Micromonospora chalcea. S1 nuclease mapping showed that the transcription initiation point of this gene is at the translation start point, with no evidence of a conventional ribosome-binding site. The aac of paromycin-producing Streptomyces rimosus forma paromomycinus shows the same characteristic; there is no homology in the promoter regions of the two genes, whereas the coding sequences are very similar.
Collapse
Affiliation(s)
- D Salauze
- Département des Biotechnologies, Institut Pasteur, Paris
| | | |
Collapse
|
45
|
Doyle D, McDowall KJ, Butler MJ, Hunter IS. Characterization of an oxytetracycline-resistance gene, otrA, of Streptomyces rimosus. Mol Microbiol 1991; 5:2923-33. [PMID: 1809836 DOI: 10.1111/j.1365-2958.1991.tb01852.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The sequence of a 2657 bp DNA fragment containing the coding and regulatory regions of the oxytetracycline (OTC)-resistance gene, otrA, from the OTC producer Streptomyces rimosus was determined. The predicted amino acid sequence of OtrA had extensive identity with tetracycline-resistance genes from other bacteria which mediate resistance via non-covalent ribosomal modification. The N-terminal domain had extremely high identity with the GTP-binding sites of elongation factors, such as EF-G and EF-Tu, suggesting that binding and hydrolysis of GTP is important to the function of the protein. Significant identity with EF-G was present throughout the polypeptide. Transcriptional activity upstream of the otrA coding region was investigated. An Escherichia coli-type promoter, otrAp1, was identified. Transcriptional readthrough of otrA from the upstream gene (otcZ) was also detected in S. rimosus cultures. A divergent promoter activity was identified with subclones of the OtrA fragment in promoter probe vectors analysed in Streptomyces lividans. However, this activity was not identified in a subclone containing more than half of the otrA coding sequence in S. lividans or at all in S. rimosus, indicating that OtrA negatively regulates the expression of the divergent transcript. The data are consistent with regulation of antibiotic production by OtrA to prevent 'suicide'.
Collapse
Affiliation(s)
- D Doyle
- Institute of Genetics, University of Glasgow, UK
| | | | | | | |
Collapse
|
46
|
FarkaÅ¡ovský M, Kormanec JÃ, Kollárová M. RNA polymerase heterogeneity in Streptomyces aureofaciens: characterization by antibody-linked polymerase assay. FEMS Microbiol Lett 1991. [DOI: 10.1111/j.1574-6968.1991.tb05125.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
47
|
Wray LV, Atkinson MR, Fisher SH. Identification and cloning of the glnR locus, which is required for transcription of the glnA gene in Streptomyces coelicolor A3(2). J Bacteriol 1991; 173:7351-60. [PMID: 1718946 PMCID: PMC209244 DOI: 10.1128/jb.173.22.7351-7360.1991] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Six Streptomyces coelicolor mutants that required glutamine for growth at the wild-type rate on all nitrogen sources (Gln-) were isolated. The phenotypes of all six mutants were similar. The glutamine synthetase (GS) levels were 20- to 100-fold lower in extracts of the Gln- mutants than in extracts of their parents. The reduced levels of GS activity in the Gln- mutants were not due to adenylylation of the GS protein, because GS activity in Gln- extracts did not increase after snake venom phosphodiesterase treatment. No transcripts of the GS structural gene (glnA) could be detected in RNA isolated from the Gln- mutants in primer extension experiments. All six gln mutations mapped adjacent to adeA. S. coelicolor chromosomal DNA complementing the Gln- mutants was isolated from a library of S. coelicolor chromosomal DNA constructed in the low-copy-number S. coelicolor plasmid pIJ922. Subcloning experiments showed that a 1.45-kb DNA fragment could complement all six Gln- mutants. This DNA fragment did not hybridize with either the cloned S. coelicolor glnA gene or the cloned S. viridochromogenes GSII gene in Southern blots. Since glnA transcription was restored in the Gln- mutants containing the complementing DNA, the gln mutations appear to lie in one or more closely linked genes that are required for glnA transcription in S. coelicolor.
Collapse
Affiliation(s)
- L V Wray
- Department of Microbiology, Boston University School of Medicine, Massachusetts 02118-2394
| | | | | |
Collapse
|
48
|
Tanaka K, Shiina T, Takahashi H. Nucleotide sequence of genes hrdA, hrdC, and hrdD from Streptomyces coelicolor A3(2) having similarity to rpoD genes. MOLECULAR & GENERAL GENETICS : MGG 1991; 229:334-40. [PMID: 1944221 DOI: 10.1007/bf00267453] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The complete nucleotide sequences were determined of hrdA, hrdC, and hrdD from Streptomyces coelicolor A3(2). They indicate the presence of a single open reading frame in each gene coding for polypeptides of 396 (43,747 daltons), 339 (38,173 daltons), and 332 amino acid residues (37,190 daltons), respectively. These amino acid sequences revealed extensive similarities with the principal sigma factors of Bacillus subtilis, Escherichia coli, Mxyococcus xanthus, Pseudomonas aeruginosa, and also the katF gene product of E. coli. Besides the highly conserved amino acid residues in the "rpoD box" region, alignment of hrd gene products and the known principal sigma factors and sigma-related factors allowed us to postulate a common basic structure for the principal sigma type factors as distinct from the alternative sigma factors.
Collapse
Affiliation(s)
- K Tanaka
- Institute of Applied Microbiology, University of Tokyo, Japan
| | | | | |
Collapse
|
49
|
Holmes DJ, Cundliffe E. Analysis of a ribosomal RNA methylase gene from Streptomyces tenebrarius which confers resistance to gentamicin. MOLECULAR & GENERAL GENETICS : MGG 1991; 229:229-37. [PMID: 1921972 DOI: 10.1007/bf00272160] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Resistance to the aminoglycoside gentamicin in the nebramycin producer, Streptomyces tenebrarius, occurs at the level of the ribosome. A resistance determinant isolated from this actinomycete was previously shown to encode a methylase enzyme which modifies residue G-1405 of 16S ribosomal RNA. This gene (kgmB) has been sequenced and expressed in Escherichia coli using lacZ transcriptional signals since, like many other actinomycete genes, kgmB is not expressed in E. coli from its own promoter. The 5' end of the kgmB transcript has been mapped revealing a single promoter which does not obviously conform to the prokaryotic consensus.
Collapse
Affiliation(s)
- D J Holmes
- Department of Biochemistry, University of Leicester, UK
| | | |
Collapse
|
50
|
Caballero JL, Malpartida F, Hopwood DA. Transcriptional organization and regulation of an antibiotic export complex in the producing Streptomyces culture. MOLECULAR & GENERAL GENETICS : MGG 1991; 228:372-80. [PMID: 1716725 DOI: 10.1007/bf00260629] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Three open reading frames (ORFs) in the actII region of the actinorhodin biosynthetic gene cluster of Streptomyces coelicolor A3(2), which are involved in the export of the antibiotic are carried on two divergent transcripts. A monocistronic transcript carries actII-ORF1, encoding a putative repressor protein, and a bicistronic transcript codes for actII-ORF2 and -ORF3, whose products have been postulated to form an antibiotic export complex. The actII-ORF1 and actII-ORF2/3 transcripts each have a single promoter and the promoters for the two transcripts overlap. Both promoters are most active in cultures that have developed to the stage of actinorhodin production. The promoters resemble consensus promoters of the vegetative class in Escherichia coli and Streptomyces. We also demonstrate that these promoters are expressed in E. coli and use this finding to reveal a regulatory role for the repressor, using the xylE reporter gene on promoter-probe shuttle vectors and regulated expression of the actII-ORF1 gene under control of Plac. The actII-ORF2/3 promoter is strongly repressed by the ORF1 product and the ORF1 product also represses its own promoter. The finding that the operator/promoter arrangement, and regulatory interconnection, of an antibiotic export/repressor gene pair in Streptomyces strikingly resemble those for tetracycline resistance in bacteria of clinical importance supports the hypothesis of an evolutionary origin of such genes in an ancestral actinomycete.
Collapse
Affiliation(s)
- J L Caballero
- John Innes Institute, John Innes Centre, Norwich, UK
| | | | | |
Collapse
|