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H, Elliot MA. Multifactorial genetic control and magnesium levels govern the production of a Streptomyces antibiotic with unusual cell density dependence. mSystems 2024; 9:e0136823. [PMID: 38493407 PMCID: PMC11019849 DOI: 10.1128/msystems.01368-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 02/15/2024] [Indexed: 03/18/2024] Open
Abstract
Streptomyces bacteria are renowned both for their antibiotic production capabilities and for their cryptic metabolic potential. Their metabolic repertoire is subject to stringent genetic control, with many of the associated biosynthetic gene clusters being repressed by the conserved nucleoid-associated protein Lsr2. In an effort to stimulate new antibiotic production in wild Streptomyces isolates, we leveraged the activity of an Lsr2 knockdown construct and successfully enhanced antibiotic production in the wild Streptomyces isolate WAC07094. We determined that this new activity stemmed from increased levels of the angucycline-like family member saquayamycin. Saquayamycin has both antibiotic and anti-cancer activities, and intriguingly, beyond Lsr2-mediated repression, we found saquayamycin production was also suppressed at high density on solid or in liquid growth media; its levels were greatest in low-density cultures. This density-dependent control was exerted at the level of the cluster-situated regulatory gene sqnR and was mediated in part through the activity of the PhoRP two-component regulatory system, where deleting phoRP led to both constitutive antibiotic production and sqnR expression. This suggests that PhoP functions to repress the expression of sqnR at high cell density. We further discovered that magnesium supplementation could alleviate this density dependence, although its action was independent of PhoP. Finally, we revealed that the nitrogen-responsive regulators GlnR and AfsQ1 could relieve the repression exerted by Lsr2 and PhoP. Intriguingly, we found that this low density-dependent production of saquayamycin was not unique to WAC07094; saquayamycin production by another wild isolate also exhibited low-density activation, suggesting that this spatial control may serve an important ecological function in their native environments.IMPORTANCEStreptomyces specialized metabolic gene clusters are subject to complex regulation, and their products are frequently not observed under standard laboratory growth conditions. For the wild Streptomyces isolate WAC07094, production of the angucycline-family compound saquayamycin is subject to a unique constellation of control factors. Notably, it is produced primarily at low cell density, in contrast to the high cell density production typical of most antibiotics. This unusual density dependence is conserved in other saquayamycin producers and is driven by the pathway-specific regulator SqnR, whose expression is influenced by both nutritional and genetic elements. Collectively, this work provides new insights into an intricate regulatory system governing antibiotic production and indicates there may be benefits to including low-density cultures in antibiotic screening platforms.
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Affiliation(s)
- Hindra
- Institute of Infectious Disease Research and Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Marie A. Elliot
- Institute of Infectious Disease Research and Department of Biology, McMaster University, Hamilton, Ontario, Canada
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2
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McLean TC, Beaton ADM, Martins C, Saalbach G, Chandra G, Wilkinson B, Hutchings MI. Evidence of a role for CutRS and actinorhodin in the secretion stress response in Streptomyces coelicolor M145. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001358. [PMID: 37418299 PMCID: PMC10433416 DOI: 10.1099/mic.0.001358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 06/20/2023] [Indexed: 07/08/2023]
Abstract
CutRS was the first two-component system to be identified in Streptomyces species and is highly conserved in this genus. It was reported >25 years ago that deletion of cutRS increases the production of the antibiotic actinorhodin in Streptomyces coelicolor. However, despite this early work, the function of CutRS has remained enigmatic until now. Here we show that deletion of cutRS upregulates the production of the actinorhodin biosynthetic enzymes up to 300-fold, explaining the increase in actinorhodin production. However, while ChIP-seq identified 85 CutR binding sites in S. coelicolor none of these are in the actinorhodin biosynthetic gene cluster, meaning the effect is indirect. The directly regulated CutR targets identified in this study are implicated in extracellular protein folding, including two of the four highly conserved HtrA-family foldases: HtrA3 and HtrB, and a putative VKOR enzyme, which is predicted to recycle DsbA following its catalysis of disulphide bond formation in secreted proteins. Thus, we tentatively propose a role for CutRS in sensing and responding to protein misfolding outside the cell. Since actinorhodin can oxidise cysteine residues and induce disulphide bond formation in proteins, its over production in the ∆cutRS mutant may be a response to protein misfolding on the extracellular face of the membrane.
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Affiliation(s)
- Thomas C. McLean
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norwich Research Park, NR4 7UH, UK
| | - Ainsley D. M. Beaton
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norwich Research Park, NR4 7UH, UK
| | - Carlo Martins
- Department Biochemistry and Metabolism, Proteomics Facility, John Innes Centre, Norwich, Norwich Research Park, NR4 7UH, UK
| | - Gerhard Saalbach
- Department Biochemistry and Metabolism, Proteomics Facility, John Innes Centre, Norwich, Norwich Research Park, NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norwich Research Park, NR4 7UH, UK
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norwich Research Park, NR4 7UH, UK
| | - Matthew I. Hutchings
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norwich Research Park, NR4 7UH, UK
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3
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Avramova MM, Stevenson CEM, Chandra G, Holmes NA, Bush MJ, Findlay KC, Buttner MJ. Global Effects of the Developmental Regulator BldB in Streptomyces venezuelae. J Bacteriol 2023; 205:e0013523. [PMID: 37249447 PMCID: PMC10294661 DOI: 10.1128/jb.00135-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 05/31/2023] Open
Abstract
In Streptomyces, the Bld (Bald) regulators control formation of the reproductive aerial hyphae. The functions of some of these regulators have been well characterized, but BldB has remained enigmatic. In addition to the bldB gene itself, Streptomyces venezuelae has 10 paralogs of bldB that sit next to paralogs of whiJ and abaA. Transcriptome sequencing (RNA-seq) revealed that loss of BldB function causes the dramatic transcriptional upregulation of the abaA paralogs and a novel inhibitor of sporulation, iosA, and that cooverexpression of just two of these genes, iosA and abaA6, was sufficient to recapitulate the bldB mutant phenotype. Further RNA-seq analysis showed that the transcription factor WhiJ9 is required for the activation of iosA seen in the bldB mutant, and biochemical studies showed that WhiJ9 mediates the activation of iosA expression by binding to direct repeats in the iosA-whiJ9 intergenic region. BldB and BldB9 hetero-oligomerize, providing a potential link between BldB and the iosA-whiJ9-bldB9 locus. This work greatly expands our overall understanding of the global effects of the BldB developmental regulator. IMPORTANCE To reproduce and disperse, the filamentous bacterium Streptomyces develops specialized reproductive structures called aerial hyphae. The formation of these structures is controlled by the bld (bald) genes, many of which encode transcription factors whose functions have been characterized. An exception is BldB, a protein whose biochemical function is unknown. In this study, we gain insight into the global effects of BldB function by examining the genome-wide transcriptional effects of deleting bldB. We identify a small set of genes that are dramatically upregulated in the absence of BldB. We show that their overexpression causes the bldB phenotype and characterize a transcription factor that mediates the upregulation of one of these target genes. Our results provide new insight into how BldB influences Streptomyces development.
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Affiliation(s)
- Marieta M. Avramova
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Clare E. M. Stevenson
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich, United Kingdom
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Neil A. Holmes
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Matthew J. Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Kim C. Findlay
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, United Kingdom
| | - Mark J. Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
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4
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Jin S, Hui M, Lu Y, Zhao Y. An overview on the two-component systems of Streptomyces coelicolor. World J Microbiol Biotechnol 2023; 39:78. [PMID: 36645528 DOI: 10.1007/s11274-023-03522-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/10/2023] [Indexed: 01/17/2023]
Abstract
The two-component system (TCS) found in various organisms is a regulatory system, which is involved in the response by the organism to stimuli, thereby regulating the internal behavior of the cell. It is commonly found in prokaryotes and is an important signaling system in bacteria. TCSs are involved in the regulation of physiological and morphological differentiation of the industrially important microbes from the genus Streptomyces, which produce a vast array of bioactive secondary metabolites (SMs). Genetic engineering of TCSs can substantially increase the yield of target SMs, which is valuable for industrial-scale production. Research on TCS has mainly been completed in the model strain Streptomyces coelicolor. In this review, we summarize the recent advances in the functional identification and elucidation of the regulatory mechanisms of various TCSs in S. coelicolor, with a focus on their roles in the biosynthesis of important SMs.
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Affiliation(s)
- Shangping Jin
- College of Bioengineering, Henan University of Technology, 100 Lianhua Street, 450001, Zhengzhou, China
| | - Ming Hui
- College of Bioengineering, Henan University of Technology, 100 Lianhua Street, 450001, Zhengzhou, China
| | - Yinhua Lu
- College of Life Sciences, Shanghai Normal University, 100 Guilin Road, 200234, Shanghai, China.
| | - Yawei Zhao
- College of Bioengineering, Henan University of Technology, 100 Lianhua Street, 450001, Zhengzhou, China.
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5
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Antibiotic Acyldepsipeptides Stimulate the Streptomyces Clp-ATPase/ClpP Complex for Accelerated Proteolysis. mBio 2022; 13:e0141322. [PMID: 36286522 PMCID: PMC9765437 DOI: 10.1128/mbio.01413-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Clp proteases consist of a proteolytic, tetradecameric ClpP core and AAA+ Clp-ATPases. Streptomycetes, producers of a plethora of secondary metabolites, encode up to five different ClpP homologs, and the composition of their unusually complex Clp protease machinery has remained unsolved. Here, we report on the composition of the housekeeping Clp protease in Streptomyces, consisting of a heterotetradecameric core built of ClpP1, ClpP2, and the cognate Clp-ATPases ClpX, ClpC1, or ClpC2, all interacting with ClpP2 only. Antibiotic acyldepsipeptides (ADEP) dysregulate the Clp protease for unregulated proteolysis. We observed that ADEP binds Streptomyces ClpP1, but not ClpP2, thereby not only triggering the degradation of nonnative protein substrates but also accelerating Clp-ATPase-dependent proteolysis. The explanation is the concomitant binding of ADEP and Clp-ATPases to opposite sides of the ClpP1P2 barrel, hence revealing a third, so far unknown mechanism of ADEP action, i.e., the accelerated proteolysis of native protein substrates by the Clp protease. IMPORTANCE Clp proteases are antibiotic and anticancer drug targets. Composed of the proteolytic core ClpP and a regulatory Clp-ATPase, the protease machinery is important for protein homeostasis and regulatory proteolysis. The acyldepsipeptide antibiotic ADEP targets ClpP and has shown promise for treating multiresistant and persistent bacterial infections. The molecular mechanism of ADEP is multilayered. Here, we present a new way how ADEP can deregulate the Clp protease system. Clp-ATPases and ADEP bind to opposite sides of Streptomyces ClpP, accelerating the degradation of natural Clp protease substrates. We also demonstrate the composition of the major Streptomyces Clp protease complex, a heteromeric ClpP1P2 core with the Clp-ATPases ClpX, ClpC1, or ClpC2 exclusively bound to ClpP2, and the killing mechanism of ADEP in Streptomyces.
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6
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Sánchez de la Nieta R, Santamaría RI, Díaz M. Two-Component Systems of Streptomyces coelicolor: An Intricate Network to Be Unraveled. Int J Mol Sci 2022; 23:ijms232315085. [PMID: 36499414 PMCID: PMC9739842 DOI: 10.3390/ijms232315085] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
Bacteria of the Streptomyces genus constitute an authentic biotech gold mine thanks to their ability to produce a myriad of compounds and enzymes of great interest at various clinical, agricultural, and industrial levels. Understanding the physiology of these organisms and revealing their regulatory mechanisms is essential for their manipulation and application. Two-component systems (TCSs) constitute the predominant signal transduction mechanism in prokaryotes, and can detect a multitude of external and internal stimuli and trigger the appropriate cellular responses for adapting to diverse environmental conditions. These global regulatory systems usually coordinate various biological processes for the maintenance of homeostasis and proper cell function. Here, we review the multiple TCSs described and characterized in Streptomyces coelicolor, one of the most studied and important model species within this bacterial group. TCSs are involved in all cellular processes; hence, unravelling the complex regulatory network they form is essential for their potential biotechnological application.
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7
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Clarke CR, Kramer CG, Kotha RR, Luthria DL. The Phytotoxin Thaxtomin A Is the Primary Virulence Determinant for Scab Disease of Beet, Carrot, and Radish Caused by Streptomyces scabiei. PHYTOPATHOLOGY 2022; 112:2288-2295. [PMID: 35694886 DOI: 10.1094/phyto-03-22-0072-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Several species of Streptomyces cause common scab, a major disease of potato, primarily through the phytotoxic effects of the phytotoxin thaxtomin A. Several phytopathogenic Streptomyces species have also been implicated as the causative agents of scab diseases of taproot crops including beet, carrot, radish, parsnip, and turnip. But the molecular mechanisms employed by Streptomyces to infect these crops is unknown. In this work, we tested the hypothesis that thaxtomin A biosynthesis is also necessary for Streptomyces-caused scab of beet, carrot, radish, and turnip. Thaxtomin A induced plant stunting and cell death of all four of these species. Streptomyces mutants in which the transcriptional regulator of thaxtomin A biosynthesis is disrupted were nonvirulent on all four crops, and complementation of the transcriptional regulator rescued thaxtomin A biosynthesis and plant pathogenicity to wild-type levels. These results demonstrate that thaxtomin A is the primary virulence determinant of scab disease of these other crops.
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Affiliation(s)
- Christopher R Clarke
- Genetic Improvement for Fruits and Vegetables Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD
| | - Charles G Kramer
- Genetic Improvement for Fruits and Vegetables Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD
| | - Raghavendhar R Kotha
- Food Composition and Methods Development Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD
| | - Devanand L Luthria
- Food Composition and Methods Development Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD
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8
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Schumacher MA, Wörmann ME, Henderson M, Salinas R, Latoscha A, Al-Bassam MM, Singh KS, Barclay E, Gunka K, Tschowri N. Allosteric regulation of glycogen breakdown by the second messenger cyclic di-GMP. Nat Commun 2022; 13:5834. [PMID: 36192422 PMCID: PMC9530166 DOI: 10.1038/s41467-022-33537-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 09/15/2022] [Indexed: 11/09/2022] Open
Abstract
Streptomyces are our principal source of antibiotics, which they generate concomitant with a complex developmental transition from vegetative hyphae to spores. c-di-GMP acts as a linchpin in this transition by binding and regulating the key developmental regulators, BldD and WhiG. Here we show that c-di-GMP also binds the glycogen-debranching-enzyme, GlgX, uncovering a direct link between c-di-GMP and glycogen metabolism in bacteria. Further, we show c-di-GMP binding is required for GlgX activity. We describe structures of apo and c-di-GMP-bound GlgX and, strikingly, their comparison shows c-di-GMP induces long-range conformational changes, reorganizing the catalytic pocket to an active state. Glycogen is an important glucose storage compound that enables animals to cope with starvation and stress. Our in vivo studies reveal the important biological role of GlgX in Streptomyces glucose availability control. Overall, we identify a function of c-di-GMP in controlling energy storage metabolism in bacteria, which is widespread in Actinobacteria.
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Affiliation(s)
- Maria A Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA.
| | - Mirka E Wörmann
- Institute for Biology/Microbiology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
- Bundesinstitut für Risikobewertung, 12277, Berlin, Germany
| | - Max Henderson
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Raul Salinas
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Andreas Latoscha
- Institute for Biology/Microbiology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Mahmoud M Al-Bassam
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, 92093, USA
| | | | - Elaine Barclay
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Katrin Gunka
- Institute of Microbiology, Leibniz Universität Hannover, 30419, Hannover, Germany
| | - Natalia Tschowri
- Institute of Microbiology, Leibniz Universität Hannover, 30419, Hannover, Germany.
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9
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Surette MD, Waglechner N, Koteva K, Wright GD. HelR is a helicase-like protein that protects RNA polymerase from rifamycin antibiotics. Mol Cell 2022; 82:3151-3165.e9. [PMID: 35907401 DOI: 10.1016/j.molcel.2022.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 03/15/2022] [Accepted: 06/12/2022] [Indexed: 10/16/2022]
Abstract
Rifamycin antibiotics such as rifampin are potent inhibitors of prokaryotic RNA polymerase (RNAP) used to treat tuberculosis and other bacterial infections. Although resistance arises in the clinic principally through mutations in RNAP, many bacteria possess highly specific enzyme-mediated resistance mechanisms that modify and inactivate rifamycins. The expression of these enzymes is controlled by a 19-bp cis-acting rifamycin-associated element (RAE). Guided by the presence of RAE sequences, we identify a helicase-like protein, HelR, in Streptomyces venezuelae that confers broad-spectrum rifamycin resistance. We show that HelR also promotes tolerance to rifamycins, enabling bacterial evasion of the toxic properties of these antibiotics. HelR forms a complex with RNAP and rescues transcription inhibition by displacing rifamycins from RNAP, thereby providing resistance by target protection . Furthermore, HelRs are broadly distributed in Actinobacteria, including several opportunistic Mycobacterial pathogens, offering yet another challenge for developing new rifamycin antibiotics.
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Affiliation(s)
- Matthew D Surette
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Nicholas Waglechner
- Toronto Invasive Bacterial Diseases Network, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Kalinka Koteva
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Gerard D Wright
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada.
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10
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Xu M, Wang W, Waglechner N, Culp EJ, Guitor AK, Wright GD. Phylogeny-Informed Synthetic Biology Reveals Unprecedented Structural Novelty in Type V Glycopeptide Antibiotics. ACS CENTRAL SCIENCE 2022; 8:615-626. [PMID: 35647273 PMCID: PMC9136965 DOI: 10.1021/acscentsci.1c01389] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Indexed: 06/01/2023]
Abstract
The rise and dissemination of glycopeptide antibiotic (GPA)-resistant pathogens in healthcare settings fuel efforts to discover GPAs that can overcome resistance. Members of the type V subclass of GPAs can evade common GPA resistance mechanisms and offer promise as new drug leads. We characterize five new type V GPAs-rimomycin-A/B/C and misaugamycin-A/B-discovered through a phylogeny-guided genome mining strategy coupled with heterologous production using our GPAHex synthetic biology platform. Rimomycin is a heptapeptide similar to kistamicin but includes an N-methyl-tyrosine at amino acid 6 (AA6) and substitutes 4-hydroxyphenylglycine for tyrosine and 3,5-dihydroxyphenylglycine at positions AA1 and AA3. Misaugamycin is characterized by an unprecedented N-C cross-link between AA2 and AA4 and unique N-terminal acylation by malonyl (misaugamycin-A) or 2-sulfoacetyl (misaugamycin-B) groups. We demonstrate that rimomycin-A/B/C and misaugamycin-A/B are potent antibiotics with activity against GPA-resistant clinical isolates and that the mode of action is consistent with the inhibition of cell division by the evasion of autolysin activity. These discoveries expand the chemical diversity of the type V GPAs, offer new chemical scaffolds for drug development, and demonstrate the application of the GPAHex platform in mining GPA chemical "dark matter".
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11
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Xu M, Wang W, Wright GD. Glycopeptide antibiotic discovery in the genomic era. Methods Enzymol 2022; 665:325-346. [PMID: 35379441 DOI: 10.1016/bs.mie.2021.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Glycopeptide antibiotics are essential drugs used to treat infections caused by multi-drug resistant Gram-positive pathogens. There is a continuous need for new antibiotics, including GPAs, to address emerging resistance and offer desirable pharmacological profiles for improved efficacy. Microbial natural products are proven sources of antibiotics, and this source has dominated drug discovery over the past century. Bacteria from the phylum Actinobacteria are particularly renowned for producing a diverse range of bioactive natural products including glycopeptide antibiotics. The traditional approach to mining this resource is through the culture and extraction of natural products followed by assay for cell-killing activity. Unfortunately, this method no longer efficiently yields new antibiotic leads, delivering instead known compounds. Whole-genome sequencing programs on the other hand are revealing thousands of unexplored natural product biosynthetic gene clusters in the chromosomes of Actinobacteria. These gene clusters encode the necessary enzymes, transport and resistance mechanisms, along with regulatory elements for the biosynthesis of a variety of antibiotics. Identification of uncharacterized or cryptic biosynthetic gene clusters to unlock the chemical "dark matter" represents a new direction for the discovery of new drug candidates. This chapter discusses the identification of glycopeptide antibiotic biosynthetic gene clusters in microbial genomes, the improved production of these antibiotics using the GPAHex synthetic biology platform, and methods for their purification.
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Affiliation(s)
- Min Xu
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Wenliang Wang
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Gerard D Wright
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada.
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12
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Hwang S, Lee Y, Kim JH, Kim G, Kim H, Kim W, Cho S, Palsson BO, Cho BK. Streptomyces as Microbial Chassis for Heterologous Protein Expression. Front Bioeng Biotechnol 2022; 9:804295. [PMID: 34993191 PMCID: PMC8724576 DOI: 10.3389/fbioe.2021.804295] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/30/2021] [Indexed: 12/29/2022] Open
Abstract
Heterologous production of recombinant proteins is gaining increasing interest in biotechnology with respect to productivity, scalability, and wide applicability. The members of genus Streptomyces have been proposed as remarkable hosts for heterologous production due to their versatile nature of expressing various secondary metabolite biosynthetic gene clusters and secretory enzymes. However, there are several issues that limit their use, including low yield, difficulty in genetic manipulation, and their complex cellular features. In this review, we summarize rational engineering approaches to optimizing the heterologous production of secondary metabolites and recombinant proteins in Streptomyces species in terms of genetic tool development and chassis construction. Further perspectives on the development of optimal Streptomyces chassis by the design-build-test-learn cycle in systems are suggested, which may increase the availability of secondary metabolites and recombinant proteins.
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Affiliation(s)
- Soonkyu Hwang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Yongjae Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Ji Hun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Gahyeon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Hyeseong Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Woori Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Suhyung Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States.,Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States.,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Byung-Kwan Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,Innovative Biomaterials Research Center, KAIST Institutes, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
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13
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Andreo-Vidal A, Binda E, Fedorenko V, Marinelli F, Yushchuk O. Genomic Insights into the Distribution and Phylogeny of Glycopeptide Resistance Determinants within the Actinobacteria Phylum. Antibiotics (Basel) 2021; 10:1533. [PMID: 34943745 PMCID: PMC8698665 DOI: 10.3390/antibiotics10121533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/06/2021] [Accepted: 12/10/2021] [Indexed: 12/26/2022] Open
Abstract
The spread of antimicrobial resistance (AMR) creates a challenge for global health security, rendering many previously successful classes of antibiotics useless. Unfortunately, this also includes glycopeptide antibiotics (GPAs), such as vancomycin and teicoplanin, which are currently being considered last-resort drugs. Emerging resistance towards GPAs risks limiting the clinical use of this class of antibiotics-our ultimate line of defense against multidrug-resistant (MDR) Gram-positive pathogens. But where does this resistance come from? It is widely recognized that the GPA resistance determinants-van genes-might have originated from GPA producers, such as soil-dwelling Gram-positive actinobacteria, that use them for self-protection. In the current work, we present a comprehensive bioinformatics study on the distribution and phylogeny of GPA resistance determinants within the Actinobacteria phylum. Interestingly, van-like genes (vlgs) were found distributed in different arrangements not only among GPA-producing actinobacteria but also in the non-producers: more than 10% of the screened actinobacterial genomes contained one or multiple vlgs, while less than 1% encoded for a biosynthetic gene cluster (BGC). By phylogenetic reconstructions, our results highlight the co-evolution of the different vlgs, indicating that the most diffused are the ones coding for putative VanY carboxypeptidases, which can be found alone in the genomes or associated with a vanS/R regulatory pair.
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Affiliation(s)
- Andrés Andreo-Vidal
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy; (A.A.-V.); (E.B.); (O.Y.)
| | - Elisa Binda
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy; (A.A.-V.); (E.B.); (O.Y.)
| | - Victor Fedorenko
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, 79005 Lviv, Ukraine;
| | - Flavia Marinelli
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy; (A.A.-V.); (E.B.); (O.Y.)
| | - Oleksandr Yushchuk
- Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy; (A.A.-V.); (E.B.); (O.Y.)
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, 79005 Lviv, Ukraine;
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14
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Pawlik KJ, Zelkowski M, Biernacki M, Litwinska K, Jaworski P, Kotowska M. GntR-like SCO3932 Protein Provides a Link between Actinomycete Integrative and Conjugative Elements and Secondary Metabolism. Int J Mol Sci 2021; 22:ijms222111867. [PMID: 34769298 PMCID: PMC8584621 DOI: 10.3390/ijms222111867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 01/16/2023] Open
Abstract
Streptomyces bacteria produce a plethora of secondary metabolites including the majority of medically important antibiotics. The onset of secondary metabolism is correlated with morphological differentiation and controlled by a complex regulatory network involving numerous regulatory proteins. Control over these pathways at the molecular level has a medical and industrial importance. Here we describe a GntR-like DNA binding transcription factor SCO3932, encoded within an actinomycete integrative and conjugative element, which is involved in the secondary metabolite biosynthesis regulation. Affinity chromatography, electrophoresis mobility shift assay, footprinting and chromatin immunoprecipitation experiments revealed, both in vitro and in vivo, SCO3932 binding capability to its own promoter region shared with the neighboring gene SCO3933, as well as promoters of polyketide metabolite genes, such as cpkD, a coelimycin biosynthetic gene, and actII-orf4—an activator of actinorhodin biosynthesis. Increased activity of SCO3932 target promoters, as a result of SCO3932 overproduction, indicates an activatory role of this protein in Streptomyces coelicolor A3(2) metabolite synthesis pathways.
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15
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Holman NDM, Wilkinson AJ, Smith MCM. Alanine-scanning mutagenesis of protein mannosyl-transferase from Streptomyces coelicolor reveals strong activity-stability correlation. MICROBIOLOGY-SGM 2021; 167. [PMID: 34676818 PMCID: PMC8698208 DOI: 10.1099/mic.0.001103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In Actinobacteria, protein O-mannosyl transferase (Pmt)-mediated protein O-glycosylation has an important role in cell envelope physiology. In S. coelicolor, defective Pmt leads to increased susceptibility to cell wall-targeting antibiotics, including vancomycin and β-lactams, and resistance to phage ϕC31. The aim of this study was to gain a deeper understanding of the structure and function of S. coelicolor Pmt. Sequence alignments and structural bioinformatics were used to identify target sites for an alanine-scanning mutagenesis study. Mutant alleles were introduced into pmt-deficient S. coelicolor strains using an integrative plasmid and scored for their ability to complement phage resistance and antibiotic hypersusceptibility phenotypes. Twenty-three highly conserved Pmt residues were each substituted for alanine. Six mutant alleles failed to complement the pmt▬ strains in either assay. Mapping the six corresponding residues onto a homology model of the three-dimensional structure of Pmt, indicated that five are positioned close to the predicted catalytic DE motif. Further mutagenesis to produce more conservative substitutions at these six residues produced Pmts that invariably failed to complement the DT1025 pmt▬ strain, indicating that strict residue conservation was necessary to preserve function. Cell fractionation and Western blotting of strains with the non-complementing pmt alleles revealed undetectable levels of the enzyme in either the membrane fractions or whole cell lysates. Meanwhile for all of the strains that complemented the antibiotic hypersusceptibility and phage resistance phenotypes, Pmt was readily detected in the membrane fraction. These data indicate a tight correlation between the activity of Pmt and its stability or ability to localize to the membrane.
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Affiliation(s)
| | - Anthony J Wilkinson
- Structural Biology Laboratory, York Biomedical Research Institute, Department of Chemistry, University of York, York YO10 5DD, UK
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16
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Park J, Yim SS, Wang HH. High-Throughput Transcriptional Characterization of Regulatory Sequences from Bacterial Biosynthetic Gene Clusters. ACS Synth Biol 2021; 10:1859-1873. [PMID: 34288650 DOI: 10.1021/acssynbio.0c00639] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Recent efforts to sequence, survey, and functionally characterize the diverse biosynthetic capabilities of bacteria have identified numerous Biosynthetic Gene Clusters (BGCs). Genes found within BGCs are typically transcriptionally silent, suggesting their expression is tightly regulated. To better elucidate the underlying mechanisms and principles that govern BGC regulation on a DNA sequence level, we employed high-throughput DNA synthesis and multiplexed reporter assays to build and to characterize a library of BGC-derived regulatory sequences. Regulatory sequence transcription levels were measured in the Actinobacteria Streptomyces albidoflavus J1074, a popular model strain from a genus rich in BGC diversity. Transcriptional activities varied over 1000-fold in range and were used to identify key features associated with expression, including GC content, transcription start sites, and sequence motifs. Furthermore, we demonstrated that transcription levels could be modulated through coexpression of global regulatory proteins. Lastly, we developed and optimized a S. albidoflavus cell-free expression system for rapid characterization of regulatory sequences. This work helps to elucidate the regulatory landscape of BGCs and provides a diverse library of characterized regulatory sequences for rational engineering and activation of cryptic BGCs.
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Affiliation(s)
- Jimin Park
- Department of Systems Biology, Columbia University Irving Medical Center, New York, New York 10032, United States
- Integrated Program in Cellular, Molecular and Biomedical Studies, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Sung Sun Yim
- Department of Systems Biology, Columbia University Irving Medical Center, New York, New York 10032, United States
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Harris H. Wang
- Department of Systems Biology, Columbia University Irving Medical Center, New York, New York 10032, United States
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032, United States
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17
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Abstract
Diverse bacterial lifestyle transitions are controlled by the nucleotide second messenger c-di-GMP, including virulence, motility, and biofilm formation. To control such fundamentally distinct processes, the set of genes under c-di-GMP control must have gone through several shifts during bacterial evolution. Here we show that the same σ–(c-di-GMP)–anti-σ switch has been co-opted during evolution to regulate distinct biological functions in unicellular and filamentous bacteria, controlling type IV pilus production in the genus Rubrobacter and the differentiation of reproductive hyphae into spores in Streptomyces. Moreover, we show that the anti-σ likely originated as a homodimer and evolved to become a monomer through an intragenic duplication event. This study thus describes the structural and functional evolution of a c-di-GMP regulatory switch. Filamentous actinobacteria of the genus Streptomyces have a complex lifecycle involving the differentiation of reproductive aerial hyphae into spores. We recently showed c-di-GMP controls this transition by arming a unique anti-σ, RsiG, to bind the sporulation-specific σ, WhiG. The Streptomyces venezuelae RsiG–(c-di-GMP)2–WhiG structure revealed that a monomeric RsiG binds c-di-GMP via two E(X)3S(X)2R(X)3Q(X)3D repeat motifs, one on each helix of an antiparallel coiled-coil. Here we show that RsiG homologs are found scattered throughout the Actinobacteria. Strikingly, RsiGs from unicellular bacteria descending from the most basal branch of the Actinobacteria are small proteins containing only one c-di-GMP binding motif, yet still bind their WhiG partners. Our structure of a Rubrobacter radiotolerans (RsiG)2–(c-di-GMP)2–WhiG complex revealed that these single-motif RsiGs are able to form an antiparallel coiled-coil through homodimerization, thereby allowing them to bind c-di-GMP similar to the monomeric twin-motif RsiGs. Further data show that in the unicellular actinobacterium R. radiotolerans, the (RsiG)2–(c-di-GMP)2–WhiG regulatory switch controls type IV pilus expression. Phylogenetic analysis indicates the single-motif RsiGs likely represent the ancestral state and an internal gene-duplication event gave rise to the twin-motif RsiGs inherited elsewhere in the Actinobacteria. Thus, these studies show how the anti-σ RsiG has evolved through an intragenic duplication event from a small protein carrying a single c-di-GMP binding motif, which functions as a homodimer, to a larger protein carrying two c-di-GMP binding motifs, which functions as a monomer. Consistent with this, our structures reveal potential selective advantages of the monomeric twin-motif anti-σ factors.
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18
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Worsley SF, Macey MC, Prudence SMM, Wilkinson B, Murrell JC, Hutchings MI. Investigating the Role of Root Exudates in Recruiting Streptomyces Bacteria to the Arabidopsis thaliana Microbiome. Front Mol Biosci 2021; 8:686110. [PMID: 34222338 PMCID: PMC8241931 DOI: 10.3389/fmolb.2021.686110] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/27/2021] [Indexed: 02/01/2023] Open
Abstract
Streptomyces species are saprophytic soil bacteria that produce a diverse array of specialized metabolites, including half of all known antibiotics. They are also rhizobacteria and plant endophytes that can promote plant growth and protect against disease. Several studies have shown that streptomycetes are enriched in the rhizosphere and endosphere of the model plant Arabidopsis thaliana. Here, we set out to test the hypothesis that they are attracted to plant roots by root exudates, and specifically by the plant phytohormone salicylate, which they might use as a nutrient source. We confirmed a previously published report that salicylate over-producing cpr5 plants are colonized more readily by streptomycetes but found that salicylate-deficient sid2-2 and pad4 plants had the same levels of root colonization by Streptomyces bacteria as the wild-type plants. We then tested eight genome sequenced Streptomyces endophyte strains in vitro and found that none were attracted to or could grow on salicylate as a sole carbon source. We next used 13CO2 DNA stable isotope probing to test whether Streptomyces species can feed off a wider range of plant metabolites but found that Streptomyces bacteria were outcompeted by faster growing proteobacteria and did not incorporate photosynthetically fixed carbon into their DNA. We conclude that, given their saprotrophic nature and under conditions of high competition, streptomycetes most likely feed on more complex organic material shed by growing plant roots. Understanding the factors that impact the competitiveness of strains in the plant root microbiome could have consequences for the effective application of biocontrol strains.
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Affiliation(s)
- Sarah F Worsley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Michael C Macey
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Samuel M M Prudence
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom.,Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - J Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Matthew I Hutchings
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom.,Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
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19
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Bednarz B, Millan-Oropeza A, Kotowska M, Świat M, Quispe Haro JJ, Henry C, Pawlik K. Coelimycin Synthesis Activatory Proteins Are Key Regulators of Specialized Metabolism and Precursor Flux in Streptomyces coelicolor A3(2). Front Microbiol 2021; 12:616050. [PMID: 33897632 PMCID: PMC8062868 DOI: 10.3389/fmicb.2021.616050] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 03/17/2021] [Indexed: 11/24/2022] Open
Abstract
Many microbial specialized metabolites are industrially relevant agents but also serve as signaling molecules in intra-species and even inter-kingdom interactions. In the antibiotic-producing Streptomyces, members of the SARP (Streptomyces antibiotic regulatory proteins) family of regulators are often encoded within biosynthetic gene clusters and serve as their direct activators. Coelimycin is the earliest, colored specialized metabolite synthesized in the life cycle of the model organism Streptomyces coelicolor A3(2). Deletion of its two SARP activators cpkO and cpkN abolished coelimycin synthesis and resulted in dramatic changes in the production of the later, stationary-phase antibiotics. The underlying mechanisms of these phenotypes were deregulation of precursor flux and quorum sensing, as shown by label-free, bottom-up shotgun proteomics. Detailed profiling of promoter activities demonstrated that CpkO is the upper-level cluster activator that induces CpkN, while CpkN activates type II thioesterase ScoT, necessary for coelimycin synthesis. What is more, we show that cpkN is regulated by quorum sensing gamma-butyrolactone receptor ScbR.
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Affiliation(s)
- Bartosz Bednarz
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Aaron Millan-Oropeza
- PAPPSO, Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Magdalena Kotowska
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Michał Świat
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Juan J Quispe Haro
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Céline Henry
- PAPPSO, Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Krzysztof Pawlik
- Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
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20
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Eyles TH, Vior NM, Lacret R, Truman AW. Understanding thioamitide biosynthesis using pathway engineering and untargeted metabolomics. Chem Sci 2021; 12:7138-7150. [PMID: 34123341 PMCID: PMC8153245 DOI: 10.1039/d0sc06835g] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/19/2021] [Indexed: 11/21/2022] Open
Abstract
Thiostreptamide S4 is a thioamitide, a family of promising antitumour ribosomally synthesised and post-translationally modified peptides (RiPPs). The thioamitides are one of the most structurally complex RiPP families, yet very few thioamitide biosynthetic steps have been elucidated, even though the biosynthetic gene clusters (BGCs) of multiple thioamitides have been identified. We hypothesised that engineering the thiostreptamide S4 BGC in a heterologous host could provide insights into its biosynthesis when coupled with untargeted metabolomics and targeted mutations of the precursor peptide. Modified BGCs were constructed, and in-depth metabolomics enabled a detailed understanding of the biosynthetic pathway to thiostreptamide S4, including the identification of a protein critical for amino acid dehydration that has homology to HopA1, an effector protein used by a plant pathogen to aid infection. We use this biosynthetic understanding to bioinformatically identify diverse RiPP-like BGCs, paving the way for future RiPP discovery and engineering.
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Affiliation(s)
- Tom H Eyles
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Natalia M Vior
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Rodney Lacret
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - Andrew W Truman
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
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21
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Hesketh A, Bucca G, Smith CP, Hong HJ. Chemotranscriptomic Profiling Defines Drug-Specific Signatures of the Glycopeptide Antibiotics Dalbavancin, Vancomycin and Chlorobiphenyl-Vancomycin in a VanB-Type-Resistant Streptomycete. Front Microbiol 2021; 12:641756. [PMID: 33717038 PMCID: PMC7947799 DOI: 10.3389/fmicb.2021.641756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/05/2021] [Indexed: 11/25/2022] Open
Abstract
Dalbavancin, vancomycin and chlorobiphenyl-vancomycin share a high degree of structural similarity and the same primary mode of drug action. All inhibit bacterial cell wall biosynthesis through complexation with intermediates in peptidoglycan biosynthesis mediated via interaction with peptidyl-d-alanyl-d-alanine (d-Ala-d-Ala) residues present at the termini of the intermediates. VanB-type glycopeptide resistance in bacteria encodes an inducible reprogramming of bacterial cell wall biosynthesis that generates precursors terminating with d-alanyl-d-lactate (d-Ala-d-Lac). This system in Streptomyces coelicolor confers protection against the natural product vancomycin but not dalbavancin or chlorobiphenyl-vancomycin, which are semi-synthetic derivatives and fail to sufficiently activate the inducible VanB-type sensory response. We used transcriptome profiling by RNAseq to identify the gene expression signatures elucidated in S. coelicolor in response to the three different glycopeptide compounds. An integrated comparison of the results defines both the contribution of the VanB resistance system to the control of changes in gene transcription and the impact at the transcriptional level of the structural diversity present in the glycopeptide antibiotics used. Dalbavancin induces markedly more extensive changes in the expression of genes required for transport processes, RNA methylation, haem biosynthesis and the biosynthesis of the amino acids arginine and glutamine. Chlorobiphenyl-vancomycin exhibits specific effects on tryptophan and calcium-dependent antibiotic biosynthesis and has a stronger repressive effect on translation. Vancomycin predictably has a uniquely strong effect on the genes controlled by the VanB resistance system and also impacts metal ion homeostasis and leucine biosynthesis. Leaderless gene transcription is disfavoured in the core transcriptional up- and down-regulation taking place in response to all the glycopeptide antibiotics, while HrdB-dependent transcripts are favoured in the down-regulated group. This study illustrates the biological impact of peripheral changes to glycopeptide antibiotic structure and could inform the design of future semi-synthetic glycopeptide derivatives.
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Affiliation(s)
- Andy Hesketh
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
| | - Giselda Bucca
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
| | - Colin P. Smith
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
| | - Hee-Jeon Hong
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
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22
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Rietmeyer L, Fix-Boulier N, Le Fournis C, Iannazzo L, Kitoun C, Patin D, Mengin-Lecreulx D, Ethève-Quelquejeu M, Arthur M, Fonvielle M. Partition of tRNAGly isoacceptors between protein and cell-wall peptidoglycan synthesis in Staphylococcus aureus. Nucleic Acids Res 2021; 49:684-699. [PMID: 33367813 PMCID: PMC7826273 DOI: 10.1093/nar/gkaa1242] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/04/2020] [Accepted: 12/09/2020] [Indexed: 11/21/2022] Open
Abstract
The sequence of tRNAs is submitted to evolutionary constraints imposed by their multiple interactions with aminoacyl-tRNA synthetases, translation elongation factor Tu in complex with GTP (EF-Tu•GTP), and the ribosome, each being essential for accurate and effective decoding of messenger RNAs. In Staphylococcus aureus, an additional constraint is imposed by the participation of tRNAGly isoacceptors in the addition of a pentaglycine side chain to cell-wall peptidoglycan precursors by transferases FmhB, FemA and FemB. Three tRNAGly isoacceptors poorly interacting with EF-Tu•GTP and the ribosome were previously identified. Here, we show that these ‘non-proteogenic’ tRNAs are preferentially recognized by FmhB based on kinetic analyses and on synthesis of stable aminoacyl-tRNA analogues acting as inhibitors. Synthesis of chimeric tRNAs and of helices mimicking the tRNA acceptor arms revealed that this discrimination involves identity determinants exclusively present in the D and T stems and loops of non-proteogenic tRNAs, which belong to an evolutionary lineage only present in the staphylococci. EF-Tu•GTP competitively inhibited FmhB by sequestration of ‘proteogenic’ aminoacyl-tRNAs in vitro. Together, these results indicate that competition for the Gly-tRNAGly pool is restricted by both limited recognition of non-proteogenic tRNAs by EF-Tu•GTP and limited recognition of proteogenic tRNAs by FmhB.
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Affiliation(s)
- Lauriane Rietmeyer
- INSERM, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers (CRC), F-75006 Paris, France
| | - Nicolas Fix-Boulier
- INSERM, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers (CRC), F-75006 Paris, France
| | - Chloé Le Fournis
- INSERM, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers (CRC), F-75006 Paris, France
| | - Laura Iannazzo
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Université de Paris, CNRS UMR 8601, Paris F-75006 France
| | - Camelia Kitoun
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Université de Paris, CNRS UMR 8601, Paris F-75006 France
| | - Delphine Patin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Dominique Mengin-Lecreulx
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Mélanie Ethève-Quelquejeu
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Université de Paris, CNRS UMR 8601, Paris F-75006 France
| | - Michel Arthur
- INSERM, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers (CRC), F-75006 Paris, France
| | - Matthieu Fonvielle
- INSERM, Sorbonne Université, Université de Paris, Centre de Recherche des Cordeliers (CRC), F-75006 Paris, France
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23
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Devine R, McDonald HP, Qin Z, Arnold CJ, Noble K, Chandra G, Wilkinson B, Hutchings MI. Re-wiring the regulation of the formicamycin biosynthetic gene cluster to enable the development of promising antibacterial compounds. Cell Chem Biol 2021; 28:515-523.e5. [PMID: 33440167 PMCID: PMC8062789 DOI: 10.1016/j.chembiol.2020.12.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/12/2020] [Accepted: 12/17/2020] [Indexed: 12/17/2022]
Abstract
The formicamycins are promising antibiotics first identified in Streptomyces formicae KY5, which produces the compounds at low levels. Here, we show that by understanding the regulation of the for biosynthetic gene cluster (BGC), we can rewire the BGC to increase production levels. The for BGC consists of 24 genes expressed on nine transcripts. The MarR regulator ForJ represses expression of seven transcripts encoding the major biosynthetic genes as well as the ForGF two-component system that initiates biosynthesis. We show that overexpression of forGF in a ΔforJ background increases formicamycin production 10-fold compared with the wild-type. De-repression, by deleting forJ, also switches on biosynthesis in liquid culture and induces the production of additional, previously unreported formicamycin congeners. Furthermore, combining de-repression with mutations in biosynthetic genes leads to biosynthesis of additional bioactive precursors. Formicamycin biosynthesis requires 24 genes expressed on nine transcripts Deleting the MarR regulator ForJ increases formicamycin biosynthesis De-repressing formicamycin biosynthesis induces production in liquid culture Re-wiring regulation and biosynthesis results in the production of new congeners
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Affiliation(s)
- Rebecca Devine
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
| | - Hannah P McDonald
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Zhiwei Qin
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Corinne J Arnold
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Katie Noble
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
| | - Matthew I Hutchings
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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24
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Draelos MM, Thanapipatsiri A, Sucipto H, Yokoyama K. Cryptic phosphorylation in nucleoside natural product biosynthesis. Nat Chem Biol 2020; 17:213-221. [PMID: 33257873 PMCID: PMC7855722 DOI: 10.1038/s41589-020-00656-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/20/2020] [Indexed: 11/11/2022]
Abstract
Kinases are annotated in many nucleoside biosynthetic gene clusters (BGCs) but generally are considered responsible only for self-resistance. Here, we report an unexpected 2’-phosphorylation of nucleoside biosynthetic intermediates in the nikkomycin and polyoxin pathways. This phosphorylation is a unique cryptic modification as it is introduced in the third of seven steps during aminohexuronic acid (AHA) nucleoside biosynthesis, retained throughout the pathway’s duration, and is removed in the last step of the pathway. Bioinformatic analysis of reported nucleoside BGCs suggests the presence of cryptic phosphorylation in other pathways and the importance of functional characterization of kinases in nucleoside biosynthetic pathways in general. This study also functionally characterized all of the enzymes responsible for AHA biosynthesis and revealed that AHA is constructed via a unique oxidative C-C bond cleavage reaction. The results suggest a divergent biosynthetic mechanism for three classes of antifungal nucleoside natural products.
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Affiliation(s)
| | | | - Hilda Sucipto
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | - Kenichi Yokoyama
- Department of Chemistry, Duke University, Durham, NC, USA. .,Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA.
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25
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Xu M, Wang W, Waglechner N, Culp EJ, Guitor AK, Wright GD. GPAHex-A synthetic biology platform for Type IV-V glycopeptide antibiotic production and discovery. Nat Commun 2020; 11:5232. [PMID: 33067466 PMCID: PMC7567792 DOI: 10.1038/s41467-020-19138-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 09/23/2020] [Indexed: 11/09/2022] Open
Abstract
Glycopeptide antibiotics (GPAs) are essential for the treatment of severe infectious diseases caused by Gram-positive bacteria. The emergence and spread of GPA resistance have propelled the search for more effective GPAs. Given their structural complexity, genetic intractability, and low titer, expansion of GPA chemical diversity using synthetic or medicinal chemistry remains challenging. Here we describe a synthetic biology platform, GPAHex (GPA Heterologous expression), which exploits the genes required for the specialized GPA building blocks, regulation, antibiotic transport, and resistance for the heterologous production of GPAs. Application of the GPAHex platform results in: (1) a 19-fold increase of corbomycin titer compared to the parental strain, (2) the discovery of a teicoplanin-class GPA from an Amycolatopsis isolate, and (3) the overproduction and characterization of a cryptic nonapeptide GPA. GPAHex provides a platform for GPA production and mining of uncharacterized GPAs and provides a blueprint for chassis design for other natural product classes. Expansion of the chemical diversity of glycopeptide antibiotics (GPAs) to deal with the emergence and spread of GPA resistance is challenging. Here, the authors report a GPA synthetic biology platform in Streptomyces coelicolor for Type IV–V glycopeptide antibiotic production and discovery.
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Affiliation(s)
- Min Xu
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Wenliang Wang
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Nicholas Waglechner
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Elizabeth J Culp
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Allison K Guitor
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Gerard D Wright
- David Braley Center for Antibiotic Discovery, M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada.
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26
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Vior NM, Cea-Torrescassana E, Eyles TH, Chandra G, Truman AW. Regulation of Bottromycin Biosynthesis Involves an Internal Transcriptional Start Site and a Cluster-Situated Modulator. Front Microbiol 2020; 11:495. [PMID: 32273872 PMCID: PMC7113386 DOI: 10.3389/fmicb.2020.00495] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 03/06/2020] [Indexed: 01/18/2023] Open
Abstract
Bottromycin is a ribosomally synthesized and post-translationally modified peptide (RiPP) produced by several streptomycetes, including the plant pathogen Streptomyces scabies. There is significant interest in this molecule as it possesses strong antibacterial activity against clinically relevant multidrug resistant pathogens and is structurally distinct from all other antibiotics. However, studies into its efficacy are hampered by poor yields. An understanding of how bottromycin biosynthesis is regulated could aid the development of strategies to increase titres. Here, we use 5′-tag-RNA-seq to identify the transcriptional organization of the gene cluster, which includes an internal transcriptional start site that precedes btmD, the gene that encodes the bottromycin precursor peptide. We show that the gene cluster does not encode a master regulator that controls pathway expression and instead encodes a regulatory gene, btmL, which functions as a modulator that specifically affects the expression of btmD but not genes up- or downstream of btmD. In order to identify non-cluster associated proteins involved in regulation, proteins were identified that bind to the main promoter of the pathway, which precedes btmC. This study provides insights into how this deceptively complex pathway is regulated in the absence of a pathway specific master regulator, and how it might coordinate with the central metabolism of the cell.
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Affiliation(s)
- Natalia M Vior
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | | | - Tom H Eyles
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Andrew W Truman
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
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27
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Gallagher KA, Schumacher MA, Bush MJ, Bibb MJ, Chandra G, Holmes NA, Zeng W, Henderson M, Zhang H, Findlay KC, Brennan RG, Buttner MJ. c-di-GMP Arms an Anti-σ to Control Progression of Multicellular Differentiation in Streptomyces. Mol Cell 2020; 77:586-599.e6. [PMID: 31810759 PMCID: PMC7005675 DOI: 10.1016/j.molcel.2019.11.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/22/2019] [Accepted: 11/04/2019] [Indexed: 12/31/2022]
Abstract
Streptomyces are our primary source of antibiotics, produced concomitantly with the transition from vegetative growth to sporulation in a complex developmental life cycle. We previously showed that the signaling molecule c-di-GMP binds BldD, a master repressor, to control initiation of development. Here we demonstrate that c-di-GMP also intervenes later in development to control differentiation of the reproductive hyphae into spores by arming a novel anti-σ (RsiG) to bind and sequester a sporulation-specific σ factor (σWhiG). We present the structure of the RsiG-(c-di-GMP)2-σWhiG complex, revealing an unusual, partially intercalated c-di-GMP dimer bound at the RsiG-σWhiG interface. RsiG binds c-di-GMP in the absence of σWhiG, employing a novel E(X)3S(X)2R(X)3Q(X)3D motif repeated on each helix of a coiled coil. Further studies demonstrate that c-di-GMP is essential for RsiG to inhibit σWhiG. These findings reveal a newly described control mechanism for σ-anti-σ complex formation and establish c-di-GMP as the central integrator of Streptomyces development.
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Affiliation(s)
- Kelley A. Gallagher
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Maria A. Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA,Corresponding author
| | - Matthew J. Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Maureen J. Bibb
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Neil A. Holmes
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Wenjie Zeng
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Max Henderson
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hengshan Zhang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kim C. Findlay
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Richard G. Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mark J. Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK,Corresponding author
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28
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Stogios PJ, Savchenko A. Molecular mechanisms of vancomycin resistance. Protein Sci 2020; 29:654-669. [PMID: 31899563 DOI: 10.1002/pro.3819] [Citation(s) in RCA: 121] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 12/18/2022]
Abstract
Vancomycin and related glycopeptides are drugs of last resort for the treatment of severe infections caused by Gram-positive bacteria such as Enterococcus species, Staphylococcus aureus, and Clostridium difficile. Vancomycin was long considered immune to resistance due to its bactericidal activity based on binding to the bacterial cell envelope rather than to a protein target as is the case for most antibiotics. However, two types of complex resistance mechanisms, each comprised of a multi-enzyme pathway, emerged and are now widely disseminated in pathogenic species, thus threatening the clinical efficiency of vancomycin. Vancomycin forms an intricate network of hydrogen bonds with the d-Ala-d-Ala region of Lipid II, interfering with the peptidoglycan layer maturation process. Resistance to vancomycin involves degradation of this natural precursor and its replacement with d-Ala-d-lac or d-Ala-d-Ser alternatives to which vancomycin has low affinity. Through extensive research over 30 years after the initial discovery of vancomycin resistance, remarkable progress has been made in molecular understanding of the enzymatic cascades responsible. Progress has been driven by structural studies of the key components of the resistance mechanisms which provided important molecular understanding such as, for example, the ability of this cascade to discriminate between vancomycin sensitive and resistant peptidoglycan precursors. Important structural insights have been also made into the molecular evolution of vancomycin resistance enzymes. Altogether this molecular data can accelerate inhibitor discovery and optimization efforts to reverse vancomycin resistance. Here, we overview our current understanding of this complex resistance mechanism with a focus on the structural and molecular aspects.
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Affiliation(s)
- Peter J Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada.,Center for Structural Genomics of Infectious Diseases (CSGID)
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada.,Center for Structural Genomics of Infectious Diseases (CSGID).,Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
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29
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In Situ Activation and Heterologous Production of a Cryptic Lantibiotic from an African Plant Ant-Derived Saccharopolyspora Species. Appl Environ Microbiol 2020; 86:AEM.01876-19. [PMID: 31732571 PMCID: PMC6974636 DOI: 10.1128/aem.01876-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/07/2019] [Indexed: 01/05/2023] Open
Abstract
The discovery of novel antibiotics to tackle the growing threat of antimicrobial resistance is impeded by difficulties in accessing the full biosynthetic potential of microorganisms. The development of new tools to unlock the biosynthesis of cryptic bacterial natural products will greatly increase the repertoire of natural product scaffolds. Here, we report a strategy for the ectopic expression of pathway-specific positive regulators that can be rapidly applied to activate the biosynthesis of cryptic lanthipeptide biosynthetic gene clusters. This allowed the discovery of a new lanthipeptide antibiotic directly from the native host and via heterologous expression. Most clinical antibiotics are derived from actinomycete natural products discovered at least 60 years ago. However, the repeated rediscovery of known compounds led the pharmaceutical industry to largely discard microbial natural products (NPs) as a source of new chemical diversity. Recent advances in genome sequencing have revealed that these organisms have the potential to make many more NPs than previously thought. Approaches to unlock NP biosynthesis by genetic manipulation of strains, by the application of chemical genetics, or by microbial cocultivation have resulted in the identification of new antibacterial compounds. Concomitantly, intensive exploration of coevolved ecological niches, such as insect-microbe defensive symbioses, has revealed these to be a rich source of chemical novelty. Here, we report the new lanthipeptide antibiotic kyamicin, which was generated through the activation of a cryptic biosynthetic gene cluster identified by genome mining Saccharopolyspora species found in the obligate domatium-dwelling ant Tetraponera penzigi of the ant plant Vachellia drepanolobium. Transcriptional activation of this silent gene cluster was achieved by ectopic expression of a pathway-specific activator under the control of a constitutive promoter. Subsequently, a heterologous production platform was developed which enabled the purification of kyamicin for structural characterization and bioactivity determination. This strategy was also successful for the production of lantibiotics from other genera, paving the way for a synthetic heterologous expression platform for the discovery of lanthipeptides that are not detected under laboratory conditions or that are new to nature. IMPORTANCE The discovery of novel antibiotics to tackle the growing threat of antimicrobial resistance is impeded by difficulties in accessing the full biosynthetic potential of microorganisms. The development of new tools to unlock the biosynthesis of cryptic bacterial natural products will greatly increase the repertoire of natural product scaffolds. Here, we report a strategy for the ectopic expression of pathway-specific positive regulators that can be rapidly applied to activate the biosynthesis of cryptic lanthipeptide biosynthetic gene clusters. This allowed the discovery of a new lanthipeptide antibiotic directly from the native host and via heterologous expression.
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30
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Santos-Aberturas J, Chandra G, Frattaruolo L, Lacret R, Pham TH, Vior NM, Eyles TH, Truman AW. Uncovering the unexplored diversity of thioamidated ribosomal peptides in Actinobacteria using the RiPPER genome mining tool. Nucleic Acids Res 2019; 47:4624-4637. [PMID: 30916321 PMCID: PMC6511847 DOI: 10.1093/nar/gkz192] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/27/2019] [Accepted: 03/13/2019] [Indexed: 01/26/2023] Open
Abstract
The rational discovery of new specialized metabolites by genome mining represents a very promising strategy in the quest for new bioactive molecules. Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a major class of natural product that derive from genetically encoded precursor peptides. However, RiPP gene clusters are particularly refractory to reliable bioinformatic predictions due to the absence of a common biosynthetic feature across all pathways. Here, we describe RiPPER, a new tool for the family-independent identification of RiPP precursor peptides and apply this methodology to search for novel thioamidated RiPPs in Actinobacteria. Until now, thioamidation was believed to be a rare post-translational modification, which is catalyzed by a pair of proteins (YcaO and TfuA) in Archaea. In Actinobacteria, the thioviridamide-like molecules are a family of cytotoxic RiPPs that feature multiple thioamides, which are proposed to be introduced by YcaO-TfuA proteins. Using RiPPER, we show that previously undescribed RiPP gene clusters encoding YcaO and TfuA proteins are widespread in Actinobacteria and encode a highly diverse landscape of precursor peptides that are predicted to make thioamidated RiPPs. To illustrate this strategy, we describe the first rational discovery of a new structural class of thioamidated natural products, the thiovarsolins from Streptomyces varsoviensis.
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Affiliation(s)
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Luca Frattaruolo
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Rodney Lacret
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Thu H Pham
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Natalia M Vior
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Tom H Eyles
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Andrew W Truman
- Department of Molecular Microbiology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
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31
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Heterologous Expression of a Cryptic Gene Cluster from Streptomyces leeuwenhoekii C34 T Yields a Novel Lasso Peptide, Leepeptin. Appl Environ Microbiol 2019; 85:AEM.01752-19. [PMID: 31562169 PMCID: PMC6856326 DOI: 10.1128/aem.01752-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 09/17/2019] [Indexed: 12/24/2022] Open
Abstract
Recent developments in genome sequencing combined with bioinformatic analysis have revealed that actinomycetes contain a plethora of unexpected BGCs and thus have the potential to produce many more natural products than previously thought. This reflects the inability to detect the production of these compounds under laboratory conditions, perhaps through the use of inappropriate growth media or the absence of the environmental cues required to elicit expression of the corresponding BGCs. One approach to overcoming this problem is to circumvent the regulatory mechanisms that control expression of the BGC in its natural host by deploying heterologous expression. The generally compact nature of lasso peptide BGCs makes them particularly amenable to this approach, and, in the example given here, analysis revealed a new member of the lasso peptide family of RiPPs. This approach should be readily applicable to other cryptic lasso peptide gene clusters and would also facilitate the design and production of nonnatural variants by changing the sequence encoding the core peptide, as has been achieved with other classes of RiPPs. Analysis of the genome sequence of Streptomyces leeuwenhoekii C34T identified biosynthetic gene clusters (BGCs) for three different lasso peptides (Lp1, Lp2, and Lp3) which were not known to be made by the strain. Lasso peptides represent relatively new members of the RiPP (ribosomally synthesized and posttranslationally modified peptides) family of natural products and have not been extensively studied. Lp3, whose production could be detected in culture supernatants from S. leeuwenhoekii C34T and after heterologous expression of its BGC in Streptomyces coelicolor, is identical to the previously characterized chaxapeptin. Lp1, whose production could not be detected or achieved heterologously, appears to be identical to a recently identified member of the citrulassin family of lasso peptides. Since production of Lp2 by S. leeuwenhoekii C34T was not observed, its BGC was also expressed in S. coelicolor. The lasso peptide was isolated and its structure confirmed by mass spectrometry and nuclear magnetic resonance analyses, revealing a novel structure that appears to represent a new family of lasso peptides. IMPORTANCE Recent developments in genome sequencing combined with bioinformatic analysis have revealed that actinomycetes contain a plethora of unexpected BGCs and thus have the potential to produce many more natural products than previously thought. This reflects the inability to detect the production of these compounds under laboratory conditions, perhaps through the use of inappropriate growth media or the absence of the environmental cues required to elicit expression of the corresponding BGCs. One approach to overcoming this problem is to circumvent the regulatory mechanisms that control expression of the BGC in its natural host by deploying heterologous expression. The generally compact nature of lasso peptide BGCs makes them particularly amenable to this approach, and, in the example given here, analysis revealed a new member of the lasso peptide family of RiPPs. This approach should be readily applicable to other cryptic lasso peptide gene clusters and would also facilitate the design and production of nonnatural variants by changing the sequence encoding the core peptide, as has been achieved with other classes of RiPPs.
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32
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Tran NT, Huang X, Hong HJ, Bush MJ, Chandra G, Pinto D, Bibb MJ, Hutchings MI, Mascher T, Buttner MJ. Defining the regulon of genes controlled by σ E , a key regulator of the cell envelope stress response in Streptomyces coelicolor. Mol Microbiol 2019; 112:461-481. [PMID: 30907454 PMCID: PMC6767563 DOI: 10.1111/mmi.14250] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2019] [Indexed: 01/01/2023]
Abstract
The extracytoplasmic function (ECF) σ factor, σE , is a key regulator of the cell envelope stress response in Streptomyces coelicolor. Although its role in maintaining cell wall integrity has been known for over a decade, a comprehensive analysis of the genes under its control has not been undertaken. Here, using a combination of chromatin immunoprecipitation-sequencing (ChIP-seq), microarray transcriptional profiling and bioinformatic analysis, we attempt to define the σE regulon. Approximately half of the genes identified encode proteins implicated in cell envelope function. Seventeen novel targets were validated by S1 nuclease mapping or in vitro transcription, establishing a σE -binding consensus. Subsequently, we used bioinformatic analysis to look for conservation of the σE target promoters identified in S. coelicolor across 19 Streptomyces species. Key proteins under σE control across the genus include the actin homolog MreB, three penicillin-binding proteins, two L,D-transpeptidases, a LytR-CpsA-Psr-family protein predicted to be involved in cell wall teichoic acid deposition and a predicted MprF protein, which adds lysyl groups to phosphatidylglycerol to neutralize membrane surface charge. Taken together, these analyses provide biological insight into the σE -mediated cell envelope stress response in the genus Streptomyces.
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Affiliation(s)
- Ngat T Tran
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Xiaoluo Huang
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.,Department Biology I, Ludwig-Maximilians-Universität München, Großhaderner Str. 2-4, Planegg-Martinsried, 82152, Germany
| | - Hee-Jeon Hong
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Matthew J Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Daniela Pinto
- Department Biology I, Ludwig-Maximilians-Universität München, Großhaderner Str. 2-4, Planegg-Martinsried, 82152, Germany
| | - Maureen J Bibb
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Matthew I Hutchings
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Thorsten Mascher
- Department Biology I, Ludwig-Maximilians-Universität München, Großhaderner Str. 2-4, Planegg-Martinsried, 82152, Germany
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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Kim SH, Lu W, Ahmadi MK, Montiel D, Ternei MA, Brady SF. Atolypenes, Tricyclic Bacterial Sesterterpenes Discovered Using a Multiplexed In Vitro Cas9-TAR Gene Cluster Refactoring Approach. ACS Synth Biol 2019; 8:109-118. [PMID: 30575381 DOI: 10.1021/acssynbio.8b00361] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Most natural product biosynthetic gene clusters identified in bacterial genomic and metagenomic sequencing efforts are silent under laboratory growth conditions. Here, we describe a scalable biosynthetic gene cluster activation method wherein the gene clusters are disassembled at interoperonic regions in vitro using CRISPR/Cas9 and then reassembled with PCR-amplified, short DNAs, carrying synthetic promoters, using transformation assisted recombination (TAR) in yeast. This simple, cost-effective, and scalable method allows for the simultaneous generation of combinatorial libraries of refactored gene clusters, eliminating the need to understand the transcriptional hierarchy of the silent genes. In two test cases, this in vitro disassembly-TAR reassembly method was used to create collections of promoter-replaced gene clusters that were tested in parallel to identify versions that enabled secondary metabolite production. Activation of the atolypene ( ato) gene cluster led to the characterization of two unprecedented bacterial cyclic sesterterpenes, atolypene A (1) and B (2), which are moderately cytotoxic to human cancer cell lines. This streamlined in vitro disassembly- in vivo reassembly method offers a simplified approach for silent gene cluster refactoring that should facilitate the discovery of natural products from silent gene clusters cloned from either metagenomes or cultured bacteria.
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Affiliation(s)
- Seong-Hwan Kim
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
| | - Wanli Lu
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
| | - Mahmoud Kamal Ahmadi
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
| | - Daniel Montiel
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
| | - Melinda A. Ternei
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
| | - Sean F. Brady
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, New York 10065, United States
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34
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Read N, Howlett R, Smith MCM. An operon encoding enzymes for synthesis of a putative extracellular carbohydrate attenuates acquired vancomycin resistance in Streptomyces coelicolor. MICROBIOLOGY-SGM 2019; 165:208-223. [PMID: 30632959 DOI: 10.1099/mic.0.000763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Actinomycete bacteria use polyprenol phosphate mannose as a lipid-linked sugar donor for extra-cytoplasmic glycosyl transferases that transfer mannose to cell envelope polymers, including glycoproteins and glycolipids. Strains of Streptomyces coelicolor with mutations in the gene ppm1, encoding polyprenol phosphate mannose synthase, and in pmt, encoding a protein O-mannosyltransferase, are resistant to phage ϕC31 and have greatly increased susceptibility to some antibiotics, including vancomycin. In this work, second-site suppressors of the vancomycin susceptibility were isolated. The suppressor strains fell into two groups. Group 1 strains had increased resistance to vancomycin, teicoplanin and β-lactams, and had mutations in the two-component sensor regulator system encoded by vanSR, leading to upegulation of the vanSRJKHAX cluster. Group 2 strains only had increased resistance to vancomycin and these mostly had mutations in sco2592 or sco2593, genes that are derepressed in the presence of phosphate and are likely to be required for the synthesis of a phosphate-containing extracellular polymer. In some suppressor strains the increased resistance was only observed in media with limited phosphate (mimicking the phenotype of wild-type S. coelicolor), but two strains, DT3017_R21 (ppm1-vanR-) and DT3017_R15 (ppm1- sco2593-), retained resistance on media with high phosphate content. These results support the view that vancomycin resistance in S. coelicolor is a trade-off between mechanisms that confer resistance and at least one that interferes with resistance mediated through the sco2594-sco2593-sco2592 operon.
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35
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Peterson E, Kaur P. Antibiotic Resistance Mechanisms in Bacteria: Relationships Between Resistance Determinants of Antibiotic Producers, Environmental Bacteria, and Clinical Pathogens. Front Microbiol 2018; 9:2928. [PMID: 30555448 PMCID: PMC6283892 DOI: 10.3389/fmicb.2018.02928] [Citation(s) in RCA: 424] [Impact Index Per Article: 70.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 11/14/2018] [Indexed: 11/13/2022] Open
Abstract
Emergence of antibiotic resistant pathogenic bacteria poses a serious public health challenge worldwide. However, antibiotic resistance genes are not confined to the clinic; instead they are widely prevalent in different bacterial populations in the environment. Therefore, to understand development of antibiotic resistance in pathogens, we need to consider important reservoirs of resistance genes, which may include determinants that confer self-resistance in antibiotic producing soil bacteria and genes encoding intrinsic resistance mechanisms present in all or most non-producer environmental bacteria. While the presence of resistance determinants in soil and environmental bacteria does not pose a threat to human health, their mobilization to new hosts and their expression under different contexts, for example their transfer to plasmids and integrons in pathogenic bacteria, can translate into a problem of huge proportions, as discussed in this review. Selective pressure brought about by human activities further results in enrichment of such determinants in bacterial populations. Thus, there is an urgent need to understand distribution of resistance determinants in bacterial populations, elucidate resistance mechanisms, and determine environmental factors that promote their dissemination. This comprehensive review describes the major known self-resistance mechanisms found in producer soil bacteria of the genus Streptomyces and explores the relationships between resistance determinants found in producer soil bacteria, non-producer environmental bacteria, and clinical isolates. Specific examples highlighting potential pathways by which pathogenic clinical isolates might acquire these resistance determinants from soil and environmental bacteria are also discussed. Overall, this article provides a conceptual framework for understanding the complexity of the problem of emergence of antibiotic resistance in the clinic. Availability of such knowledge will allow researchers to build models for dissemination of resistance genes and for developing interventions to prevent recruitment of additional or novel genes into pathogens.
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Affiliation(s)
- Elizabeth Peterson
- Department of Biology, Georgia State University, Atlanta, GA, United States
| | - Parjit Kaur
- Department of Biology, Georgia State University, Atlanta, GA, United States
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36
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Characterization of the Widely Distributed Novel ECF42 Group of Extracytoplasmic Function σ Factors in Streptomyces venezuelae. J Bacteriol 2018; 200:JB.00437-18. [PMID: 30126941 DOI: 10.1128/jb.00437-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/15/2018] [Indexed: 11/20/2022] Open
Abstract
Extracytoplasmic function σ factors (ECFs) represent the third most abundant fundamental principle of bacterial signal transduction, outranked only by one- and two-component systems. A recent census of ECFs revealed a large number of novel groups whose functions and regulatory mechanisms have not yet been elucidated. Here, we report the characterization of members of the novel group ECF42. ECF42 is a highly abundant and widely distributed ECF group that is present in 11 phyla but is predominantly found in Actinobacteria Analysis of the genomic context conservation did not identify a putative anti-σ factor. Instead, ECF42 genes are cotranscribed with genes encoding a conserved DGPF protein. We have experimentally verified the target promoter of these ECFs (TGTCGA in the -35 region and CGA/TC in the -10 region), which was found upstream of the ECF42-encoding operons in Streptomyces venezuelae, suggesting that ECF42s are positively autoregulated. RNA sequencing (RNA-seq) was performed to define the regulons of the three ECF42 proteins in S. venezuelae, which identified mostly genes encoding DGPF proteins. In contrast to typical ECFs, ECF42 proteins harbor a long C-terminal extension, which is crucial for their activity. Our work provides the first analysis of the function and regulatory mechanism of this novel ECF group that contains a regulatory C-terminal extension.IMPORTANCE In contrast to the one- and two-component signal transduction systems in bacteria, the importance and diversity of ECFs have only recently been recognized in the course of comprehensive phylogenetic and comparative genomics studies. Thus, most of the ECFs still have not been experimentally characterized regarding their physiological functions and regulation mechanisms so far. The physiological roles, target promoter, and target regulons of a novel group of ECFs, ECF42, in S. venezuelae have been investigated in this work. More importantly, members of this group are characterized by a C-terminal extension, which has been verified to harbor a regulatory role in ECF42s. Hence, our work provides an important source for further research on such C-terminal extension containing ECFs.
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Trichlorination of a Teicoplanin-Type Glycopeptide Antibiotic by the Halogenase StaI Evades Resistance. Antimicrob Agents Chemother 2018; 62:AAC.01540-18. [PMID: 30275088 DOI: 10.1128/aac.01540-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/22/2018] [Indexed: 01/31/2023] Open
Abstract
Glycopeptide antibiotics (GPAs) include clinically important drugs used for the treatment of infections caused by Gram-positive pathogens. These antibiotics are specialized metabolites produced by several genera of actinomycete bacteria. While many GPAs are highly chemically modified, A47934 is a relatively unadorned GPA lacking sugar or acyl modifications, common to other members of the class, but which is chlorinated at three distinct sites. The biosynthesis of A47934 is encoded by a 68-kb gene cluster in Streptomyces toyocaensis NRRL 15009. The cluster includes all necessary genes for the synthesis of A47934, including two predicted halogenase genes, staI and staK In this study, we report that only one of the halogenase genes, staI, is necessary and essential for A47934 biosynthesis. Chlorination of the A47934 scaffold is important for antibiotic activity, as assessed by binding affinity for the target N-acyl-d-Ala-d-Ala. Surprisingly, chlorination is also vital to avoid activation of enterococcal and Streptomyces VanB-type GPA resistance through induction of resistance genes. Phenotypic assays showed stronger induction of GPA resistance by the dechlorinated compared to the chlorinated GPA. Correspondingly, the relative expression of the enterococcal vanA resistance gene was shown to be increased by the dechlorinated compared to the chlorinated compound. These results provide insight into the biosynthesis of GPAs and the biological function of GPA chlorination for this medically important class of antibiotic.
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38
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Zong C, Cheung-Lee WL, Elashal HE, Raj M, Link AJ. Albusnodin: an acetylated lasso peptide from Streptomyces albus. Chem Commun (Camb) 2018; 54:1339-1342. [PMID: 29350227 DOI: 10.1039/c7cc08620b] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We describe a lasso peptide, albusnodin, that is post-translationally modified with an acetyl group, the first example of a lasso peptide with this modification. Using heterologous expression, we further show that the acetyltransferase colocalized with the albusnodin gene cluster is required for the biosynthesis of this lasso peptide. This type of lasso peptide is widespread in Actinobacteria with 44 examples found in currently sequenced genomes.
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Affiliation(s)
- Chuhan Zong
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
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39
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The SCO1731 methyltransferase modulates actinorhodin production and morphological differentiation of Streptomyces coelicolor A3(2). Sci Rep 2018; 8:13686. [PMID: 30209340 PMCID: PMC6135851 DOI: 10.1038/s41598-018-32027-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/18/2018] [Indexed: 02/07/2023] Open
Abstract
Streptomyces coelicolor is a Gram-positive microorganism often used as a model of physiological and morphological differentiation in streptomycetes, prolific producers of secondary metabolites with important biological activities. In the present study, we analysed Streptomyces coelicolor growth and differentiation in the presence of the hypo-methylating agent 5′-aza-2′-deoxycytidine (5-aza-dC) in order to investigate whether cytosine methylation has a role in differentiation. We found that cytosine demethylation caused a delay in spore germination, aerial mycelium development, sporulation, as well as a massive impairment of actinorhodin production. Thus, we searched for putative DNA methyltransferase genes in the genome and constructed a mutant of the SCO1731 gene. The analysis of the SCO1731::Tn5062 mutant strain demonstrated that inactivation of SCO1731 leads to a strong decrease of cytosine methylation and almost to the same phenotype obtained after 5-aza-dC treatment. Altogether, our data demonstrate that cytosine methylation influences morphological differentiation and actinorhodin production in S. coelicolor and expand our knowledge on this model bacterial system.
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40
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Ji CH, Kim JP, Kang HS. Library of Synthetic Streptomyces Regulatory Sequences for Use in Promoter Engineering of Natural Product Biosynthetic Gene Clusters. ACS Synth Biol 2018; 7:1946-1955. [PMID: 29966097 DOI: 10.1021/acssynbio.8b00175] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Promoter engineering has emerged as a powerful tool to activate transcriptionally silent natural product biosynthetic gene clusters found in bacterial genomes. Since biosynthetic gene clusters are composed of multiple operons, their promoter engineering requires the use of a set of regulatory sequences with a similar level of activities. Although several successful examples of promoter engineering have been reported, its widespread use has been limited due to the lack of a library of regulatory sequences suitable for use in promoter engineering of large, multiple operon-containing biosynthetic gene clusters. Here, we present the construction of a library of constitutively active, synthetic Streptomyces regulatory sequences. The promoter assay system has been developed using a single-module nonribosomal peptide synthetase that produces the peptide blue pigment indigoidine, allowing for the rapid screening of a large pool of regulatory sequences. The highly randomized regulatory sequences in both promoter and ribosome binding site regions were screened for their ability to produce the blue pigment, and they are classified into the strong, medium, and weak regulatory sequences based on the strength of a blue color. We demonstrated the utility of our synthetic regulatory sequences for promoter engineering of natural product biosynthetic gene clusters using the actinorhodin gene cluster as a model cluster. We believe that the set of Streptomyces regulatory sequences we report here will facilitate the discovery of new natural products from silent, cryptic biosynthetic gene clusters found in sequenced Streptomyces genomes.
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Affiliation(s)
- Chang-Hun Ji
- Department of Biomedical Science and Engineering, Konkuk University, Seoul 05029, Korea
| | - Jong-Pyung Kim
- Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Chungbuk 28116, Korea
| | - Hahk-Soo Kang
- Department of Biomedical Science and Engineering, Konkuk University, Seoul 05029, Korea
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41
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Rioseras B, Shliaha PV, Gorshkov V, Yagüe P, López-García MT, Gonzalez-Quiñonez N, Kovalchuk S, Rogowska-Wrzesinska A, Jensen ON, Manteca A. Quantitative Proteome and Phosphoproteome Analyses of Streptomyces coelicolor Reveal Proteins and Phosphoproteins Modulating Differentiation and Secondary Metabolism. Mol Cell Proteomics 2018; 17:1591-1611. [PMID: 29784711 PMCID: PMC6072539 DOI: 10.1074/mcp.ra117.000515] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 05/15/2018] [Indexed: 02/03/2023] Open
Abstract
Streptomycetes are multicellular bacteria with complex developmental cycles. They are of biotechnological importance as they produce most bioactive compounds used in biomedicine, e.g. antibiotic, antitumoral and immunosupressor compounds. Streptomyces genomes encode many Ser/Thr/Tyr kinases, making this genus an outstanding model for the study of bacterial protein phosphorylation events. We used mass spectrometry based quantitative proteomics and phosphoproteomics to characterize bacterial differentiation and activation of secondary metabolism of Streptomyces coelicolor We identified and quantified 3461 proteins corresponding to 44.3% of the S. coelicolor proteome across three developmental stages: vegetative hypha (first mycelium); secondary metabolite producing hyphae (second mycelium); and sporulating hyphae. A total of 1350 proteins exhibited more than 2-fold expression changes during the bacterial differentiation process. These proteins include 136 regulators (transcriptional regulators, transducers, Ser/Thr/Tyr kinases, signaling proteins), as well as 542 putative proteins with no clear homology to known proteins which are likely to play a role in differentiation and secondary metabolism. Phosphoproteomics revealed 85 unique protein phosphorylation sites, 58 of them differentially phosphorylated during differentiation. Computational analysis suggested that these regulated protein phosphorylation events are implicated in important cellular processes, including cell division, differentiation, regulation of secondary metabolism, transcription, protein synthesis, protein folding and stress responses. We discovered a novel regulated phosphorylation site in the key bacterial cell division protein FtsZ (pSer319) that modulates sporulation and regulates actinorhodin antibiotic production. We conclude that manipulation of distinct protein phosphorylation events may improve secondary metabolite production in industrial streptomycetes, including the activation of cryptic pathways during the screening for new secondary metabolites from streptomycetes.
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Affiliation(s)
- Beatriz Rioseras
- From the ‡Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Pavel V Shliaha
- §Department of Biochemistry and Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Vladimir Gorshkov
- §Department of Biochemistry and Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Paula Yagüe
- From the ‡Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - María T López-García
- From the ‡Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Nathaly Gonzalez-Quiñonez
- From the ‡Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Sergey Kovalchuk
- §Department of Biochemistry and Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Adelina Rogowska-Wrzesinska
- §Department of Biochemistry and Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Ole N Jensen
- §Department of Biochemistry and Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark
| | - Angel Manteca
- From the ‡Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain;
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42
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Analysis of the Tunicamycin Biosynthetic Gene Cluster of Streptomyces chartreusis Reveals New Insights into Tunicamycin Production and Immunity. Antimicrob Agents Chemother 2018; 62:AAC.00130-18. [PMID: 29844049 PMCID: PMC6105854 DOI: 10.1128/aac.00130-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 05/10/2018] [Indexed: 11/20/2022] Open
Abstract
The tunicamycin biosynthetic gene cluster of Streptomyces chartreusis consists of 14 genes (tunA to tunN) with a high degree of apparent translational coupling. Transcriptional analysis revealed that all of these genes are likely to be transcribed as a single operon from two promoters, tunp1 and tunp2. In-frame deletion analysis revealed that just six of these genes (tunABCDEH) are essential for tunicamycin production in the heterologous host Streptomyces coelicolor, while five (tunFGKLN) with likely counterparts in primary metabolism are not necessary, but presumably ensure efficient production of the antibiotic at the onset of tunicamycin biosynthesis. Three genes are implicated in immunity, namely, tunI and tunJ, which encode a two-component ABC transporter presumably required for export of the antibiotic, and tunM, which encodes a putative S-adenosylmethionine (SAM)-dependent methyltransferase. Expression of tunIJ or tunM in S. coelicolor conferred resistance to exogenous tunicamycin. The results presented here provide new insights into tunicamycin biosynthesis and immunity.
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43
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Chase OM, Espinasse A, Wilke KE, Carlson EE. Exploration of the Effects of γ-Phosphate-Modified ATP Analogues on Histidine Kinase Autophosphorylation. Biochemistry 2018; 57:4368-4373. [PMID: 29944360 DOI: 10.1021/acs.biochem.8b00485] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
While two-component systems (TCSs), composed of a sensor histidine kinase (HK) and a response regulator, are the main signaling pathways in bacteria, global TCS activity remains poorly described. Here, we report the kinetic parameters of the HK autophosphorylation reaction using previously uncharacterized γ-phosphate-modified ATP analogues to further elucidate their utility as activity-based probes for global TCS analysis. Given the increased stability of thiophosphorylated histidine in comparison to that of the native phosphoryl modification, which is attributed to the decreased electrophilicity of this moiety, we anticipated that ATPγS may be turned over much more slowly by the HKs. Surprisingly, we found this not to be the case, with the turnover numbers decreasing <1 order of magnitude. Instead, we found that alkylation of the thiophosphate had a much more dramatic effect on turnover and, in one case, the binding affinity of this substrate analogue (BODIPY-FL-ATPγS).
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Affiliation(s)
- Olivia M Chase
- Department of Chemistry , University of Minnesota , 207 Pleasant Street Southeast , Minneapolis , Minnesota 55455 , United States
| | - Adeline Espinasse
- Department of Chemistry , University of Minnesota , 207 Pleasant Street Southeast , Minneapolis , Minnesota 55455 , United States
| | - Kaelyn E Wilke
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , Indiana 47405 , United States
| | - Erin E Carlson
- Department of Chemistry , University of Minnesota , 207 Pleasant Street Southeast , Minneapolis , Minnesota 55455 , United States.,Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , Indiana 47405 , United States.,Department of Medicinal Chemistry , University of Minnesota , 208 Harvard Street Southeast , Minneapolis , Minnesota 55454 , United States.,Department of Biochemistry, Molecular Biology, and Biophysics , University of Minnesota , 321 Church Street Southeast , Minneapolis , Minnesota 55454 , United States
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44
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Santos-Beneit F. Genome sequencing analysis of Streptomyces coelicolor mutants that overcome the phosphate-depending vancomycin lethal effect. BMC Genomics 2018; 19:457. [PMID: 29898657 PMCID: PMC6001138 DOI: 10.1186/s12864-018-4838-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 05/29/2018] [Indexed: 11/10/2022] Open
Abstract
Background Glycopeptide antibiotics inhibit bacterial cell-wall synthesis, and are important for the treatment of infections caused by multi drug-resistant strains of enterococci, streptococci and staphylococci. The main mechanism by which bacteria resist the action of glycopeptides is by producing a modified cell-wall in which the dipeptide D-Alanine-D-Alanine is substituted by D-Alanine-D-Lactate or D-Alanine-D-Serine. Recently, it has been shown that inorganic phosphate (Pi) induces hypersensitivity to vancomycin in Streptomyces coelicolor (which is highly resistant to the antibiotic in low-Pi media). This finding was surprising because the bacterium possesses the entire set of genes responsible for vancomycin resistance (VR); including those coding for the histidine kinase/response regulator pair VanS/VanR that activates the system. Results This work shows that high Pi amounts in the medium hamper the activation of the van promoters and consequently inhibit VR in S. coelicolor; i.e. the repression effect being stronger when basic or acidic forms of the nutrient are used. In addition, this work shows that lysozyme resistance is also highly regulated by the Pi concentration in the medium. At least five different mutations contribute to the overcoming of this repression effect over VR (but not over lysozyme resistance). Therefore, the interconnection of VR and lysozyme resistance mechanisms might be inexistent or complex. In particular, two kinds of mutant in which Pi control of VR has been lost (one class expresses the van genes in a constitutive manner; the other retains inducibility by vancomycin) have been isolated and further characterized in this study. Sequencing revealed that the first class of mutation conferred a single amino acid substitution in the second transmembrane helix of the VanS protein; whereas the other class hampered the expression or activity of a putative homolog (SCO1213) to the staphylococcal GatD protein. Complementation, phenotypic and bioinformatics analyses identified SCO1213, and its upstream gene (i.e. murT), as relevant genetic determinants involved with VR in S. coelicolor. Conclusion The genomic approach of this study together with other genetic and phenotypic analyses has allowed the identification of the uncharacterized murT-gatD Streptomyces genes and the characterization of their involvement with the Pi control of VR in S. coelicolor. Electronic supplementary material The online version of this article (10.1186/s12864-018-4838-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fernando Santos-Beneit
- Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle Upon Tyne, UK. .,Present address: Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
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45
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Discovery and Biosynthesis of the Antibiotic Bicyclomycin in Distantly Related Bacterial Classes. Appl Environ Microbiol 2018; 84:AEM.02828-17. [PMID: 29500259 PMCID: PMC5930311 DOI: 10.1128/aem.02828-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 02/21/2018] [Indexed: 01/23/2023] Open
Abstract
Bicyclomycin (BCM) is a clinically promising antibiotic that is biosynthesized by Streptomyces cinnamoneus DSM 41675. BCM is structurally characterized by a core cyclo(l-Ile-l-Leu) 2,5-diketopiperazine (DKP) that is extensively oxidized. Here, we identify the BCM biosynthetic gene cluster, which shows that the core of BCM is biosynthesized by a cyclodipeptide synthase, and the oxidative modifications are introduced by five 2-oxoglutarate-dependent dioxygenases and one cytochrome P450 monooxygenase. The discovery of the gene cluster enabled the identification of BCM pathways encoded by the genomes of hundreds of Pseudomonas aeruginosa isolates distributed globally, and heterologous expression of the pathway from P. aeruginosa SCV20265 demonstrated that the product is chemically identical to BCM produced by S. cinnamoneus. Overall, putative BCM gene clusters have been found in at least seven genera spanning Actinobacteria and Proteobacteria (Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria). This represents a rare example of horizontal gene transfer of an intact biosynthetic gene cluster across such distantly related bacteria, and we show that these gene clusters are almost always associated with mobile genetic elements. IMPORTANCE Bicyclomycin is the only natural product antibiotic that selectively inhibits the transcription termination factor Rho. This mechanism of action, combined with its proven biological safety and its activity against clinically relevant Gram-negative bacterial pathogens, makes it a very promising antibiotic candidate. Here, we report the identification of the bicyclomycin biosynthetic gene cluster in the known bicyclomycin-producing organism Streptomyces cinnamoneus, which will enable the engineered production of new bicyclomycin derivatives. The identification of this gene cluster also led to the discovery of hundreds of bicyclomycin pathways encoded in highly diverse bacteria, including in the opportunistic pathogen Pseudomonas aeruginosa. This wide distribution of a complex biosynthetic pathway is very unusual and provides an insight into how a pathway for an antibiotic can be transferred between diverse bacteria.
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46
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Howlett R, Anttonen K, Read N, Smith MCM. Disruption of the GDP-mannose synthesis pathway in Streptomyces coelicolor results in antibiotic hyper-susceptible phenotypes. MICROBIOLOGY-SGM 2018; 164:614-624. [PMID: 29493491 PMCID: PMC5982138 DOI: 10.1099/mic.0.000636] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Actinomycete bacteria use polyprenol phosphate mannose as a lipid linked sugar donor for extra-cytoplasmic glycosyl transferases that transfer mannose to cell envelope polymers, including glycoproteins and glycolipids. We showed recently that strains of Streptomyces coelicolor with mutations in the gene ppm1 encoding polyprenol phosphate mannose synthase were both resistant to phage φC31 and have greatly increased susceptibility to antibiotics that mostly act on cell wall biogenesis. Here we show that mutations in the genes encoding enzymes that act upstream of Ppm1 in the polyprenol phosphate mannose synthesis pathway can also confer phage resistance and antibiotic hyper-susceptibility. GDP-mannose is a substrate for Ppm1 and is synthesised by GDP-mannose pyrophosphorylase (GMP; ManC) which uses GTP and mannose-1-phosphate as substrates. Phosphomannomutase (PMM; ManB) converts mannose-6-phosphate to mannose-1-phosphate. S. coelicolor strains with knocked down GMP activity or with a mutation in sco3028 encoding PMM acquire phenotypes that resemble those of the ppm1- mutants i.e. φC31 resistant and susceptible to antibiotics. Differences in the phenotypes of the strains were observed, however. While the ppm1- strains have a small colony phenotype, the sco3028 :: Tn5062 mutants had an extremely small colony phenotype indicative of an even greater growth defect. Moreover we were unable to generate a strain in which GMP activity encoded by sco3039 and sco4238 is completely knocked out, indicating that GMP is also an important enzyme for growth. Possibly GDP-mannose is at a metabolic branch point that supplies alternative nucleotide sugar donors.
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Affiliation(s)
| | - Katri Anttonen
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | | | - Margaret C M Smith
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.,Department of Biology, University of York, York, UK
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47
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Howlett R, Read N, Varghese A, Kershaw C, Hancock Y, Smith MCM. Streptomyces coelicolor strains lacking polyprenol phosphate mannose synthase and protein O-mannosyl transferase are hyper-susceptible to multiple antibiotics. MICROBIOLOGY-SGM 2018; 164:369-382. [PMID: 29458553 PMCID: PMC5882110 DOI: 10.1099/mic.0.000605] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Polyprenol phosphate mannose (PPM) is a lipid-linked sugar donor used by extra-cytoplasmic glycosyl tranferases in bacteria. PPM is synthesized by polyprenol phosphate mannose synthase, Ppm1, and in most Actinobacteria is used as the sugar donor for protein O-mannosyl transferase, Pmt, in protein glycosylation. Ppm1 and Pmt have homologues in yeasts and humans, where they are required for protein O-mannosylation. Actinobacteria also use PPM for lipoglycan biosynthesis. Here we show that ppm1 mutants of Streptomyces coelicolor have increased susceptibility to a number of antibiotics that target cell wall biosynthesis. The pmt mutants also have mildly increased antibiotic susceptibilities, in particular to β-lactams and vancomycin. Despite normal induction of the vancomycin gene cluster, vanSRJKHAX, the pmt and ppm1 mutants remained highly vancomycin sensitive indicating that the mechanism of resistance is blocked post-transcriptionally. Differential RNA expression analysis indicated that catabolic pathways were downregulated and anabolic ones upregulated in the ppm1 mutant compared to the parent or complemented strains. Of note was the increase in expression of fatty acid biosynthetic genes in the ppm1- mutant. A change in lipid composition was confirmed using Raman spectroscopy, which showed that the ppm1- mutant had a greater relative proportion of unsaturated fatty acids compared to the parent or the complemented mutant. Taken together, these data suggest that an inability to synthesize PPM (ppm1) and loss of the glycoproteome (pmt- mutant) can detrimentally affect membrane or cell envelope functions leading to loss of intrinsic and, in the case of vancomycin, acquired antibiotic resistance.
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Affiliation(s)
| | | | - Anpu Varghese
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | | | - Y Hancock
- Department of Physics, University of York, York, UK.,York Centre for Complex Systems Analysis, University of York, York, UK
| | - Margaret C M Smith
- Department of Biology, University of York, York, UK.,Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
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48
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Bitok JK, Lemetre C, Ternei MA, Brady SF. Identification of biosynthetic gene clusters from metagenomic libraries using PPTase complementation in a Streptomyces host. FEMS Microbiol Lett 2018; 364:3983257. [PMID: 28817927 DOI: 10.1093/femsle/fnx155] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/19/2017] [Indexed: 01/08/2023] Open
Abstract
The majority of environmental bacteria are not readily cultured in the lab, leaving the natural products they make inaccessible using culture-dependent discovery methods. Cloning and heterologous expression of DNA extracted from environmental samples (environmental DNA, eDNA) provides a means of circumventing this discovery bottleneck. To facilitate the identification of clones containing biosynthetic gene clusters, we developed a model heterologous expression reporter strain Streptomyces albus::bpsA ΔPPTase. This strain carries a 4΄-phosphopantetheinyl transferase (PPTase)-dependent blue pigment synthase A gene, bpsA, in a PPTase deletion background. eDNA clones that express a functional PPTase restore production of the blue pigment, indigoidine. As PPTase genes often occur in biosynthetic gene clusters (BGCs), indigoidine production can be used to identify eDNA clones containing BGCs. We screened a soil eDNA library hosted in S. albus::bpsA ΔPPTase and identified clones containing non-ribosomal peptide synthetase (NRPS), polyketide synthase (PKS) and mixed NRPS/PKS biosynthetic gene clusters. One NRPS gene cluster was shown to confer the production of myxochelin A to S. albus::bpsA ΔPPTase.
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Affiliation(s)
- J Kipchirchir Bitok
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Christophe Lemetre
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Melinda A Ternei
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Sean F Brady
- Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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Peterson E, Kaur P. Antibiotic Resistance Mechanisms in Bacteria: Relationships Between Resistance Determinants of Antibiotic Producers, Environmental Bacteria, and Clinical Pathogens. Front Microbiol 2018; 9:2928. [PMID: 30555448 DOI: 10.3389/fmicb.2018.02928/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 11/14/2018] [Indexed: 05/20/2023] Open
Abstract
Emergence of antibiotic resistant pathogenic bacteria poses a serious public health challenge worldwide. However, antibiotic resistance genes are not confined to the clinic; instead they are widely prevalent in different bacterial populations in the environment. Therefore, to understand development of antibiotic resistance in pathogens, we need to consider important reservoirs of resistance genes, which may include determinants that confer self-resistance in antibiotic producing soil bacteria and genes encoding intrinsic resistance mechanisms present in all or most non-producer environmental bacteria. While the presence of resistance determinants in soil and environmental bacteria does not pose a threat to human health, their mobilization to new hosts and their expression under different contexts, for example their transfer to plasmids and integrons in pathogenic bacteria, can translate into a problem of huge proportions, as discussed in this review. Selective pressure brought about by human activities further results in enrichment of such determinants in bacterial populations. Thus, there is an urgent need to understand distribution of resistance determinants in bacterial populations, elucidate resistance mechanisms, and determine environmental factors that promote their dissemination. This comprehensive review describes the major known self-resistance mechanisms found in producer soil bacteria of the genus Streptomyces and explores the relationships between resistance determinants found in producer soil bacteria, non-producer environmental bacteria, and clinical isolates. Specific examples highlighting potential pathways by which pathogenic clinical isolates might acquire these resistance determinants from soil and environmental bacteria are also discussed. Overall, this article provides a conceptual framework for understanding the complexity of the problem of emergence of antibiotic resistance in the clinic. Availability of such knowledge will allow researchers to build models for dissemination of resistance genes and for developing interventions to prevent recruitment of additional or novel genes into pathogens.
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Affiliation(s)
- Elizabeth Peterson
- Department of Biology, Georgia State University, Atlanta, GA, United States
| | - Parjit Kaur
- Department of Biology, Georgia State University, Atlanta, GA, United States
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Schwarz PN, Buchmann A, Roller L, Kulik A, Gross H, Wohlleben W, Stegmann E. The Immunosuppressant Brasilicardin: Determination of the Biosynthetic Gene Cluster in the Heterologous HostAmycolatopsis japonicum. Biotechnol J 2017; 13. [DOI: 10.1002/biot.201700527] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/05/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Paul N. Schwarz
- Microbiology/Biotechnology; Interfaculty Institute of Microbiology and Infection Medicine (IMIT); Eberhard Karls University of Tübingen; Tübingen Germany
| | - Anina Buchmann
- Department of Pharmaceutical Biology; Pharmaceutical Institute; Eberhard Karls University of Tübingen; Tübingen Germany
| | - Luisa Roller
- Microbiology/Biotechnology; Interfaculty Institute of Microbiology and Infection Medicine (IMIT); Eberhard Karls University of Tübingen; Tübingen Germany
| | - Andreas Kulik
- Microbiology/Biotechnology; Interfaculty Institute of Microbiology and Infection Medicine (IMIT); Eberhard Karls University of Tübingen; Tübingen Germany
| | - Harald Gross
- Department of Pharmaceutical Biology; Pharmaceutical Institute; Eberhard Karls University of Tübingen; Tübingen Germany
- German Centre for Infection Research (DZIF); Partner Site Tübingen; Tübingen Germany
| | - Wolfgang Wohlleben
- Microbiology/Biotechnology; Interfaculty Institute of Microbiology and Infection Medicine (IMIT); Eberhard Karls University of Tübingen; Tübingen Germany
- German Centre for Infection Research (DZIF); Partner Site Tübingen; Tübingen Germany
| | - Evi Stegmann
- Microbiology/Biotechnology; Interfaculty Institute of Microbiology and Infection Medicine (IMIT); Eberhard Karls University of Tübingen; Tübingen Germany
- German Centre for Infection Research (DZIF); Partner Site Tübingen; Tübingen Germany
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