1
|
Ultee E, van der Aart LT, Zhang L, van Dissel D, Diebolder CA, van Wezel GP, Claessen D, Briegel A. Teichoic acids anchor distinct cell wall lamellae in an apically growing bacterium. Commun Biol 2020; 3:314. [PMID: 32555532 PMCID: PMC7300013 DOI: 10.1038/s42003-020-1038-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 05/28/2020] [Indexed: 11/17/2022] Open
Abstract
The bacterial cell wall is a multicomponent structure that provides structural support and protection. In monoderm species, the cell wall is made up predominantly of peptidoglycan, teichoic acids and capsular glycans. Filamentous monoderm Actinobacteria incorporate new cell-wall material at their tips. Here we use cryo-electron tomography to reveal the architecture of the actinobacterial cell wall of Streptomyces coelicolor. Our data shows a density difference between the apex and subapical regions. Removal of teichoic acids results in a patchy cell wall and distinct lamellae. Knock-down of tagO expression using CRISPR-dCas9 interference leads to growth retardation, presumably because build-in of teichoic acids had become rate-limiting. Absence of extracellular glycans produced by MatAB and CslA proteins results in a thinner wall lacking lamellae and patches. We propose that the Streptomyces cell wall is composed of layers of peptidoglycan and extracellular polymers that are structurally supported by teichoic acids.
Collapse
Affiliation(s)
- Eveline Ultee
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Lizah T van der Aart
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Le Zhang
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Dino van Dissel
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Christoph A Diebolder
- Netherlands Centre for Electron Nanoscopy (NeCEN), Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Gilles P van Wezel
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Dennis Claessen
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
- Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Ariane Briegel
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
- Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands.
| |
Collapse
|
2
|
Kerr L, Hoskisson PA. Reconciling DNA replication and transcription in a hyphal organism: visualizing transcription complexes in live Streptomyces coelicolor. Microbiology (Reading) 2019; 165:1086-1094. [PMID: 31429818 DOI: 10.1099/mic.0.000834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Reconciling transcription and DNA replication in the growing hyphae of the filamentous bacterium Streptomyces presents several physical constraints on growth due to their apically extending and branching, multigenomic cells and chromosome replication being independent of cell division. Using a GFP translational fusion to the β'-subunit of RNA polymerase (rpoC-egfp), in its native chromosomal location, we observed growing Streptomyces hyphae using time-lapse microscopy throughout the lifecycle and under different growth conditions. The RpoC-eGFP fusion co-localized with DNA around 1.8 µm behind the extending tip, whereas replisomes localize around 4-5 µm behind the tip, indicating that at the growing tip, transcription and chromosome replication are to some degree spatially separated. Dual-labelled RpoC-egfp/DnaN-mCherry strains also indicate that there is limited co-localization of transcription and chromosome replication at the extending hyphal tip. This likely facilitates the use of the same DNA molecule for active transcription and chromosome replication in growing cells, independent of cell division. This represents a novel, but hitherto unknown mechanism for reconciling two fundamental processes that utilize the same macromolecular template that allows for rapid growth without compromising chromosome replication in filamentous bacteria and may have implications for evolution of filamentous growth in micro-organisms, where uncoupling of DNA replication from cell division is required.
Collapse
Affiliation(s)
- Leena Kerr
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
- School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Riccarton, Edinburgh, UK
| | - Paul A Hoskisson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| |
Collapse
|
3
|
Rioseras B, López-García MT, Yagüe P, Sánchez J, Manteca Á. Mycelium differentiation and development of Streptomyces coelicolor in lab-scale bioreactors: programmed cell death, differentiation, and lysis are closely linked to undecylprodigiosin and actinorhodin production. Bioresour Technol 2014; 151:191-8. [PMID: 24240146 PMCID: PMC3858829 DOI: 10.1016/j.biortech.2013.10.068] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/18/2013] [Accepted: 10/21/2013] [Indexed: 05/11/2023]
Abstract
Streptomycetes are mycelium-forming bacteria that produce two thirds of clinically relevant secondary metabolites. Secondary metabolite production is activated at specific developmental stages of Streptomyces life cycle. Despite this, Streptomyces differentiation in industrial bioreactors tends to be underestimated and the most important parameters managed are only indirectly related to differentiation: modifications to the culture media, optimization of productive strains by random or directed mutagenesis, analysis of biophysical parameters, etc. In this work the relationship between differentiation and antibiotic production in lab-scale bioreactors was defined. Streptomyces coelicolor was used as a model strain. Morphological differentiation was comparable to that occurring during pre-sporulation stages in solid cultures: an initial compartmentalized mycelium suffers a programmed cell death, and remaining viable segments then differentiate to a second multinucleated antibiotic-producing mycelium. Differentiation was demonstrated to be one of the keys to interpreting biophysical fermentation parameters and to rationalizing the optimization of secondary metabolite production in bioreactors.
Collapse
Affiliation(s)
- Beatriz Rioseras
- Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - María Teresa López-García
- Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Paula Yagüe
- Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Jesús Sánchez
- Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| | - Ángel Manteca
- Área de Microbiología, Departamento de Biología Funcional e IUOPA, Facultad de Medicina, Universidad de Oviedo, 33006 Oviedo, Spain
| |
Collapse
|
4
|
Abstract
Streptomyces coelicolor is the genetically best characterized species of a populous genus belonging to the gram-positive Actinobacteria. Streptomycetes are filamentous soil organisms, well known for the production of a plethora of biologically active secondary metabolic compounds. The Streptomyces developmental life cycle is uniquely complex and involves coordinated multicellular development with both physiological and morphological differentiation of several cell types, culminating in the production of secondary metabolites and dispersal of mature spores. This review presents a current appreciation of the signaling mechanisms used to orchestrate the decision to undergo morphological differentiation, and the regulators and regulatory networks that direct the intriguing development of multigenomic hyphae first to form specialized aerial hyphae and then to convert them into chains of dormant spores. This current view of S. coelicolor development is destined for rapid evolution as data from '-omics' studies shed light on gene regulatory networks, new genetic screens identify hitherto unknown players, and the resolution of our insights into the underlying cell biological processes steadily improve.
Collapse
Affiliation(s)
| | - Klas Flärdh
- Department of Biology, Lund University, Lund, Sweden
| |
Collapse
|
5
|
Schrempf H, Koebsch I, Walter S, Engelhardt H, Meschke H. Extracellular Streptomyces vesicles: amphorae for survival and defence. Microb Biotechnol 2011; 4:286-99. [PMID: 21342473 PMCID: PMC3818868 DOI: 10.1111/j.1751-7915.2011.00251.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 01/12/2011] [Indexed: 11/27/2022] Open
Abstract
Blue-pigmented exudates arise as droplets on sporulated lawns of Streptomyces coelicolor M110 grown on agar plates. Our electron microscopical and biochemical studies suggest that droplets contain densely packed vesicles with large assemblies of different protein types and/or the polyketide antibiotic actinorhodin. Frozen-hydrated vesicles were unilamellar with a typical bilayer membrane, and ranged from 80 to 400 nm in diameter with a preferred width of 150-300 nm. By means of cryo-electron tomography, three types were reconstructed three-dimensionally: vesicles that were filled with particulate material, likely protein assemblies, those that contained membrane-bound particles, and a vesicle that showed a higher contrast inside, but lacked particles. Our LC/MS analyses of generated tryptic peptides led to the identification of distinct proteins that carry often a predicted N-terminal signal peptide with a twin-arginine motif or lack a canonical signal sequence. The proteins are required for a range of processes: the acquisition of inorganic as well as organic phosphate, iron ions, and of distinct carbon sources, energy metabolism and redox balance, defence against oxidants and tellurites, the tailoring of actinorhodin, folding and assembly of proteins, establishment of turgor, and different signalling cascades. Our novel findings have immense implications for understanding new avenues of environmental biology of streptomycetes and for biotechnological applications.
Collapse
Affiliation(s)
- Hildgund Schrempf
- FB Biology/Chemistry, Applied Genetics of Microorganisms, University Osnabrück, Barbarastr. 13, D-49069 Osnabrück, Germany.
| | | | | | | | | |
Collapse
|
6
|
Ausmees N, Wahlstedt H, Bagchi S, Elliot MA, Buttner MJ, Flärdh K. SmeA, a small membrane protein with multiple functions in Streptomyces sporulation including targeting of a SpoIIIE/FtsK-like protein to cell division septa. Mol Microbiol 2007; 65:1458-73. [PMID: 17824926 DOI: 10.1111/j.1365-2958.2007.05877.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sporulation in aerial hyphae of Streptomyces coelicolor involves profound changes in regulation of fundamental morphogenetic and cell cycle processes to convert the filamentous and multinucleoid cells to small unigenomic spores. Here, a novel sporulation locus consisting of smeA (encoding a small putative membrane protein) and sffA (encoding a SpoIIIE/FtsK-family protein) is characterized. Deletion of smeA-sffA gave rise to pleiotropic effects on spore maturation, and influenced the segregation of chromosomes and placement of septa during sporulation. Both smeA and sffA were expressed specifically in apical cells of sporogenic aerial hyphae simultaneously with or slightly after Z-ring assembly. The presence of smeA-like genes in streptomycete chromosomes, plasmids and transposons, often paired with a gene for a SpoIIIE/FtsK- or Tra-like protein, indicates that SmeA and SffA functions might be related to DNA transfer. During spore development SffA accumulated specifically at sporulation septa where it colocalized with FtsK. However, sffA did not show redundancy with ftsK, and SffA function appeared distinct from the DNA translocase activity displayed by FtsK during closure of sporulation septa. The septal localization of SffA was dependent on SmeA, suggesting that SmeA may act as an assembly factor for SffA and possibly other proteins required during spore maturation.
Collapse
Affiliation(s)
- Nora Ausmees
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, 75124, Uppsala, Sweden.
| | | | | | | | | | | |
Collapse
|
7
|
Manteca A, Claessen D, Lopez-Iglesias C, Sanchez J. Aerial hyphae in surface cultures of Streptomyces lividans and Streptomyces coelicolor originate from viable segments surviving an early programmed cell death event. FEMS Microbiol Lett 2007; 274:118-25. [PMID: 17663705 DOI: 10.1111/j.1574-6968.2007.00825.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Morphogenesis in streptomycetes is characterized by the formation of aerial hyphae that emerge from the substrate mycelium. Despite many years of study, a detailed picture of the events that occur during the transition from substrate to aerial mycelium has yet to be defined. In this paper, it was shown that a specific cell death event takes place during early growth of the substrate mycelium in Streptomyces coelicolor and Streptomyces lividans. Subsequently, a second mycelium starts to develop from the remaining viable segments of these substrate hyphae in the form of islands, which progressively cover the plate surface. Interestingly, the genes coding for the chaplin and rodlin proteins, which are involved in the formation of the hydrophobic layer characteristic of aerial structures, are specifically expressed in the second mycelium islands, strongly suggesting that this second mycelium should be considered the early precursor of the mature hydrophobic aerial mycelium.
Collapse
Affiliation(s)
- Angel Manteca
- Departamento de Biologia Funcional e Instituto de Biotecnologia de Asturias (IUBA), Universidad de Oviedo, Oviedo, Spain
| | | | | | | |
Collapse
|
8
|
Arnold A, Jun S. Time scale of entropic segregation of flexible polymers in confinement: implications for chromosome segregation in filamentous bacteria. Phys Rev E Stat Nonlin Soft Matter Phys 2007; 76:031901. [PMID: 17930265 DOI: 10.1103/physreve.76.031901] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 06/26/2007] [Indexed: 05/25/2023]
Abstract
We report molecular dynamics simulations of the segregation of two overlapping chains in cylindrical confinement. We find that the entropic repulsion between chains can be sufficiently strong to cause segregation on a time scale that is short compared to the one for diffusion. This result implies that entropic driving forces are sufficiently strong to cause rapid bacterial chromosome segregation.
Collapse
Affiliation(s)
- Axel Arnold
- FOM-Institute AMOLF, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
| | | |
Collapse
|
9
|
Noens EE, Mersinias V, Willemse J, Traag BA, Laing E, Chater KF, Smith CP, Koerten HK, van Wezel GP. Loss of the controlled localization of growth stage-specific cell-wall synthesis pleiotropically affects developmental gene expression in an ssgA mutant of Streptomyces coelicolor. Mol Microbiol 2007; 64:1244-59. [PMID: 17542918 DOI: 10.1111/j.1365-2958.2007.05732.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Members of the family of SsgA-like proteins (SALPs) are found exclusively in sporulating actinomycetes, and SsgA itself activates sporulation-specific cell division. We previously showed that SALPs play a chaperonin-like role in supporting the function of enzymes involved in peptidoglycan maintenance (PBPs and autolysins). Here we show that SsgA localizes dynamically during development, and most likely marks the sites where changes in local cell-wall morphogenesis are required, in particular septum formation and germination. In sporogenic aerial hyphae, SsgA initially localizes as strong foci to the growing tips, followed by distribution as closely spaced foci in a pattern similar to an early stage of FtsZ assembly. Spore septa formed in these hyphae colocalize with single SsgA-GFP foci, and when the maturing spores are separated, these foci are distributed symmetrically, resulting in two foci per mature spore. Evidence is provided that SsgA also controls the correct localization of germination sites. Transcriptome analysis revealed that expression of around 300 genes was significantly altered in mutants in ssgA and its regulatory gene ssgR. The list includes surprisingly many known developmental genes, most of which were upregulated, highlighting SsgA as a key player in the control of Streptomyces development.
Collapse
Affiliation(s)
- Elke E Noens
- Department of Biochemistry, Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Hesketh A, Chen WJ, Ryding J, Chang S, Bibb M. The global role of ppGpp synthesis in morphological differentiation and antibiotic production in Streptomyces coelicolor A3(2). Genome Biol 2007; 8:R161. [PMID: 17683547 PMCID: PMC2374992 DOI: 10.1186/gb-2007-8-8-r161] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Revised: 06/11/2007] [Accepted: 08/03/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Regulation of production of the translational apparatus via the stringent factor ppGpp in response to amino acid starvation is conserved in many bacteria. However, in addition to this core function, it is clear that ppGpp also exhibits genus-specific regulatory effects. In this study we used Affymetrix GeneChips to more fully characterize the regulatory influence of ppGpp synthesis on the biology of Streptomyces coelicolor A3(2), with emphasis on the control of antibiotic biosynthesis and morphological differentiation. RESULTS Induction of ppGpp synthesis repressed transcription of the major sigma factor hrdB, genes with functions associated with active growth, and six of the thirteen conservons present in the S. coelicolor genome. Genes induced following ppGpp synthesis included the alternative sigma factor SCO4005, many for production of the antibiotics CDA and actinorhodin, the regulatory genes SCO4198 and SCO4336, and two alternative ribosomal proteins. Induction of the CDA and actinorhodin clusters was accompanied by an increase in transcription of the pathway regulators cdaR and actII-ORF4, respectively. Comparison of transcriptome profiles of a relA null strain, M570, incapable of ppGpp synthesis with its parent M600 suggested the occurrence of metabolic stress in the mutant. The failure of M570 to sporulate was associated with a stalling between production of the surfactant peptide SapB, and of the hydrophobins: it overproduced SapB but failed to express the chaplin and rodlin genes. CONCLUSION In S. coelicolor, ppGpp synthesis influences the expression of several genomic elements that are particularly characteristic of streptomycete biology, notably antibiotic gene clusters, conservons, and morphogenetic proteins.
Collapse
Affiliation(s)
- Andrew Hesketh
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK
| | - Wenqiong Joan Chen
- Verenium Corporation, San Diego, CA 92121, USA
- Biology Department, San Diego State University, San Diego, CA 92182, USA
| | | | - Sherman Chang
- Verenium Corporation, San Diego, CA 92121, USA
- Dermtech International, San Diego, CA 92121, USA
| | - Mervyn Bibb
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK
| |
Collapse
|
11
|
Widdick DA, Dilks K, Chandra G, Bottrill A, Naldrett M, Pohlschröder M, Palmer T. The twin-arginine translocation pathway is a major route of protein export in Streptomyces coelicolor. Proc Natl Acad Sci U S A 2006; 103:17927-32. [PMID: 17093047 PMCID: PMC1693849 DOI: 10.1073/pnas.0607025103] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The twin-arginine translocation (Tat) pathway is a protein transport system for the export of folded proteins. Substrate proteins are targeted to the Tat translocase by N-terminal signal peptides harboring a distinctive R-R-x-Phi-Phi "twin-arginine" amino acid motif. Using a combination of proteomic techniques, the protein contents from the cell wall of the model Gram-positive bacterium Streptomyces coelicolor were identified and compared with that of mutant strains defective in Tat transport. The proteomic experiments pointed to 43 potentially Tat-dependent extracellular proteins. Of these, 25 were verified as bearing bona fide Tat-targeting signal peptides after independent screening with a facile, rapid, and sensitive reporter assay. The identified Tat substrates, among others, include polymer-degrading enzymes, phosphatases, and binding proteins as well as enzymes involved in secondary metabolism. Moreover, in addition to predicted extracellular substrates, putative lipoproteins were shown to be Tat-dependent. This work provides strong experimental evidence that the Tat system is used as a major general export pathway in Streptomyces.
Collapse
Affiliation(s)
- David A. Widdick
- Departments of *Molecular Microbiology and
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom; and
| | - Kieran Dilks
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Andrew Bottrill
- Biological Chemistry, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Mike Naldrett
- Biological Chemistry, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | | | - Tracy Palmer
- Departments of *Molecular Microbiology and
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom; and
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
12
|
Ruban-Ośmiałowska B, Jakimowicz D, Smulczyk-Krawczyszyn A, Chater KF, Zakrzewska-Czerwińska J. Replisome localization in vegetative and aerial hyphae of Streptomyces coelicolor. J Bacteriol 2006; 188:7311-6. [PMID: 17015671 PMCID: PMC1636232 DOI: 10.1128/jb.00940-06] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using a functional fusion of DnaN to enhanced green fluorescent protein, we examined the subcellular localization of the replisome machinery in the vegetative mycelium and aerial mycelium of the multinucleoid organism Streptomyces coelicolor. Chromosome replication took place in many compartments of both types of hypha, with the apical compartments of the aerial mycelium exhibiting the highest replication activity. Within a single compartment, the number of "current" ongoing DNA replications was lower than the expected chromosome number, and the appearance of fluorescent foci was often heterogeneous, indicating that this process is asynchronous within compartments and that only selected chromosomes undergo replication.
Collapse
Affiliation(s)
- Beata Ruban-Ośmiałowska
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, ul. Weigla 12, 53-114, Wrocław, Poland.
| | | | | | | | | |
Collapse
|