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Michels PAM, Ginger ML. Evolution: ‘Millefoglie’ origin of mitochondrial cristae. Curr Biol 2023; 33:R219-R221. [PMID: 36977381 DOI: 10.1016/j.cub.2023.02.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Striated intracytoplasmic membranes in alphaproteobacteria are often reminiscent of millefoglie pastries. A new study reveals a protein complex homologous to that responsible for mitochondrial cristae formation drives intracytoplasmic membrane formation, thereby establishing bacterial ancestry for the biogenesis of mitochondrial cristae.
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Affiliation(s)
- Paul A M Michels
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3FL, UK.
| | - Michael L Ginger
- School of Applied Sciences, University of Huddersfield, Huddersfield HD1 3DH, UK.
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2
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Zhang L, Willemse J, Yagüe P, de Waal E, Claessen D, van Wezel GP. The SepF-like proteins SflA and SflB prevent ectopic localization of FtsZ and DivIVA during sporulation of Streptomyces coelicolor. Biochem Biophys Res Commun 2023; 645:79-87. [PMID: 36680940 DOI: 10.1016/j.bbrc.2023.01.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
Bacterial cytokinesis starts with the polymerization of the tubulin-like FtsZ, which forms the cell division scaffold. SepF aligns FtsZ polymers and also acts as a membrane anchor for the Z-ring. While in most bacteria cell division takes place at midcell, during sporulation of Streptomyces many septa are laid down almost simultaneously in multinucleoid aerial hyphae. The genomes of streptomycetes encode two additional SepF paralogs, SflA and SflB, which can interact with SepF. Here we show that the sporogenic aerial hyphae of sflA and sflB mutants of Streptomyces coelicolor frequently branch, a phenomenon never seen in the wild-type strain. The branching coincided with ectopic localization of DivIVA along the lateral wall of sporulating aerial hyphae. Constitutive expression of SflA and SflB largely inhibited hyphal growth, further correlating SflAB activity to that of DivIVA. SflAB localized in foci prior to and after the time of sporulation-specific cell division, while SepF co-localized with active septum synthesis. Foci of FtsZ and DivIVA frequently persisted between adjacent spores in spore chains of sflA and sflB mutants, at sites occupied by SflAB in wild-type cells. Taken together, our data show that SflA and SflB play an important role in the control of growth and cell division during Streptomyces development.
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Affiliation(s)
- Le Zhang
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands
| | - Joost Willemse
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands
| | - Paula Yagüe
- Departamento de Biología Funcional e IUOPA, Área de Microbiología, Facultad de Medicina, Universidad de Oviedo, Oviedo, 33006, Spain
| | - Ellen de Waal
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands
| | - Dennis Claessen
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands
| | - Gilles P van Wezel
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands.
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Alpha-Helical Protein KfrC Acts as a Switch between the Lateral and Vertical Modes of Dissemination of Broad-Host-Range RA3 Plasmid from IncU (IncP-6) Incompatibility Group. Int J Mol Sci 2021; 22:ijms22094880. [PMID: 34063039 PMCID: PMC8124265 DOI: 10.3390/ijms22094880] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/27/2021] [Accepted: 05/03/2021] [Indexed: 12/24/2022] Open
Abstract
KfrC proteins are encoded by the conjugative broad-host-range plasmids that also encode alpha-helical filament-forming KfrA proteins as exemplified by the RA3 plasmid from the IncU incompatibility group. The RA3 variants impaired in kfrA, kfrC, or both affected the host's growth and demonstrated the altered stability in a species-specific manner. In a search for partners of the alpha-helical KfrC protein, the host's membrane proteins and four RA3-encoded proteins were found, including the filamentous KfrA protein, segrosome protein KorB, and the T4SS proteins, the coupling protein VirD4 and ATPase VirB4. The C-terminal, 112-residue dimerization domain of KfrC was involved in the interactions with KorB, the master player of the active partition, and VirD4, a key component of the conjugative transfer process. In Pseudomonas putida, but not in Escherichia coli, the lack of KfrC decreased the stability but improved the transfer ability. We showed that KfrC and KfrA were involved in the plasmid maintenance and conjugative transfer and that KfrC may play a species-dependent role of a switch between vertical and horizontal modes of RA3 spreading.
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4
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Abstract
Almost all bacteria are surrounded by a cell wall, which protects cells from environmental harm. Formation of the cell wall requires the precursor molecule lipid II, which in bacteria is universally synthesized by the conserved and essential lipid II synthase MurG. The cell wall is a stress-bearing structure and a unifying trait in bacteria. Without exception, synthesis of the cell wall involves formation of the precursor molecule lipid II by the activity of the essential biosynthetic enzyme MurG, which is encoded in the division and cell wall synthesis (dcw) gene cluster. Here, we present the discovery of a cell wall enzyme that can substitute for MurG. A mutant of Kitasatospora viridifaciens lacking a significant part of the dcw cluster, including murG, surprisingly produced lipid II and wild-type peptidoglycan. Genomic analysis identified a distant murG homologue, which encodes a putative enzyme that shares only around 31% amino acid sequence identity with MurG. We show that this enzyme can replace the canonical MurG, and we therefore designated it MglA. Orthologues of mglA are present in 38% of all genomes of Kitasatospora and members of the sister genus Streptomyces. CRISPR interference experiments showed that K. viridifaciens mglA can also functionally replace murG in Streptomyces coelicolor, thus validating its bioactivity and demonstrating that it is active in multiple genera. All together, these results identify MglA as a bona fide lipid II synthase, thus demonstrating plasticity in cell wall synthesis.
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Mishra D, Pahujani S, Mitra N, Srivastava A, Srinivasan R. Identification of a Potential Membrane-Targeting Sequence in the C-Terminus of the F Plasmid Segregation Protein SopA. J Membr Biol 2021; 254:243-257. [PMID: 33427942 DOI: 10.1007/s00232-020-00157-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 11/11/2020] [Indexed: 10/22/2022]
Abstract
Stable maintenance and partitioning of the 'Fertility' plasmid or the F plasmid in its host Escherichia coli require the function of a ParA superfamily of proteins known as SopA. The mechanism by which SopA mediates plasmid segregation is well studied. SopA is a nucleoid-binding protein and binds DNA in an ATP-dependent but sequence non-specific manner. ATP hydrolysis stimulated by the binding of the SopBC complex mediates the release of SopA from the nucleoid. Cycles of ATP-binding and hydrolysis generate an ATPase gradient that moves the plasmid through a chemophoresis force. Nucleoid binding of SopA thus assumes a central role in its plasmid-partitioning function. However, earlier work also suggests that the F plasmid can be partitioned into anucleate cells, thus implicating nucleoid independent partitioning. Interestingly, SopA is also reported to be associated with the inner membrane of the bacteria. Here, we report the identification of a possible membrane-targeting sequence, a predicted amphipathic helix, at the C-terminus of SopA. Molecular dynamics simulations indicate that the predicted amphipathic helical motif of SopA has weak affinity for membranes. Moreover, we experimentally show that SopA can associate with bacterial membranes, is detectable in the membrane fractions of bacterial lysates, and is sensitive to the membrane potential. Further, unlike the wild-type SopA, a deletion of the C-terminal 29 amino acids results in the loss of F plasmids from bacterial cells.
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Affiliation(s)
- Dipika Mishra
- School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institutes, Bhubaneswar, Odisha, 752050, India
| | - Sakshi Pahujani
- School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institutes, Bhubaneswar, Odisha, 752050, India.,Molecular Biophysics Unit, Indian Institute of Science-Bangalore, C. V. Raman Road, Bangalore, Karnataka, 560012, India
| | - Nivedita Mitra
- School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institutes, Bhubaneswar, Odisha, 752050, India
| | - Anand Srivastava
- Molecular Biophysics Unit, Indian Institute of Science-Bangalore, C. V. Raman Road, Bangalore, Karnataka, 560012, India.
| | - Ramanujam Srinivasan
- School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institutes, Bhubaneswar, Odisha, 752050, India.
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Fajardo-Cavazos P, Nicholson WL. Mechanotransduction in Prokaryotes: A Possible Mechanism of Spaceflight Adaptation. Life (Basel) 2021; 11:33. [PMID: 33430182 PMCID: PMC7825584 DOI: 10.3390/life11010033] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/29/2020] [Accepted: 01/04/2021] [Indexed: 02/08/2023] Open
Abstract
Our understanding of the mechanisms of microgravity perception and response in prokaryotes (Bacteria and Archaea) lag behind those which have been elucidated in eukaryotic organisms. In this hypothesis paper, we: (i) review how eukaryotic cells sense and respond to microgravity using various pathways responsive to unloading of mechanical stress; (ii) we observe that prokaryotic cells possess many structures analogous to mechanosensitive structures in eukaryotes; (iii) we review current evidence indicating that prokaryotes also possess active mechanosensing and mechanotransduction mechanisms; and (iv) we propose a complete mechanotransduction model including mechanisms by which mechanical signals may be transduced to the gene expression apparatus through alterations in bacterial nucleoid architecture, DNA supercoiling, and epigenetic pathways.
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Affiliation(s)
| | - Wayne L. Nicholson
- Space Life Sciences Laboratory, Department of Microbiology and Cell Science, University of Florida, 505 Odyssey Way, Merritt Island, FL 32953, USA;
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A dynamic, ring-forming MucB / RseB-like protein influences spore shape in Bacillus subtilis. PLoS Genet 2020; 16:e1009246. [PMID: 33315869 PMCID: PMC7769602 DOI: 10.1371/journal.pgen.1009246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/28/2020] [Accepted: 11/03/2020] [Indexed: 01/17/2023] Open
Abstract
How organisms develop into specific shapes is a central question in biology. The maintenance of bacterial shape is connected to the assembly and remodelling of the cell envelope. In endospore-forming bacteria, the pre-spore compartment (the forespore) undergoes morphological changes that result in a spore of defined shape, with a complex, multi-layered cell envelope. However, the mechanisms that govern spore shape remain poorly understood. Here, using a combination of fluorescence microscopy, quantitative image analysis, molecular genetics and transmission electron microscopy, we show that SsdC (formerly YdcC), a poorly-characterized new member of the MucB / RseB family of proteins that bind lipopolysaccharide in diderm bacteria, influences spore shape in the monoderm Bacillus subtilis. Sporulating cells lacking SsdC fail to adopt the typical oblong shape of wild-type forespores and are instead rounder. 2D and 3D-fluorescence microscopy suggest that SsdC forms a discontinuous, dynamic ring-like structure in the peripheral membrane of the mother cell, near the mother cell proximal pole of the forespore. A synthetic sporulation screen identified genetic relationships between ssdC and genes involved in the assembly of the spore coat. Phenotypic characterization of these mutants revealed that spore shape, and SsdC localization, depend on the coat basement layer proteins SpoVM and SpoIVA, the encasement protein SpoVID and the inner coat protein SafA. Importantly, we found that the ΔssdC mutant produces spores with an abnormal-looking cortex, and abolishing cortex synthesis in the mutant largely suppresses its shape defects. Thus, SsdC appears to play a role in the proper assembly of the spore cortex, through connections to the spore coat. Collectively, our data suggest functional diversification of the MucB / RseB protein domain between diderm and monoderm bacteria and identify SsdC as an important factor in spore shape development. Cell shape is an important cellular attribute linked to cellular function and environmental adaptation. Bacterial endospores are one of the toughest cell types on Earth, with a defined shape and complex, highly-resistant, multi-layered cell envelope. Although decades of research have focused on defining the composition and assembly of the multi-layered spore envelope, little is known about how these layers contribute to spore shape. Here, we identify SsdC, a poorly-characterized new member of the MucB / RseB family of proteins that bind lipopolysaccharide in diderm bacteria. We show that SsdC is an important factor in spore shape development in the monoderm, model organism Bacillus subtilis. Our data suggest that SsdC influences the assembly of the spore cortex, through connections to the spore coat, by forming an intriguing, dynamic ring-like structure adjacent to the developing spore. Furthermore, our identification of SsdC suggests evolutionary diversification of the MucB /RseB protein domain between diderm and monoderm bacteria.
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Romano-Armada N, Yañez-Yazlle MF, Irazusta VP, Rajal VB, Moraga NB. Potential of Bioremediation and PGP Traits in Streptomyces as Strategies for Bio-Reclamation of Salt-Affected Soils for Agriculture. Pathogens 2020; 9:E117. [PMID: 32069867 PMCID: PMC7169405 DOI: 10.3390/pathogens9020117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/31/2020] [Accepted: 02/08/2020] [Indexed: 12/11/2022] Open
Abstract
Environmental limitations influence food production and distribution, adding up to global problems like world hunger. Conditions caused by climate change require global efforts to be improved, but others like soil degradation demand local management. For many years, saline soils were not a problem; indeed, natural salinity shaped different biomes around the world. However, overall saline soils present adverse conditions for plant growth, which then translate into limitations for agriculture. Shortage on the surface of productive land, either due to depletion of arable land or to soil degradation, represents a threat to the growing worldwide population. Hence, the need to use degraded land leads scientists to think of recovery alternatives. In the case of salt-affected soils (naturally occurring or human-made), which are traditionally washed or amended with calcium salts, bio-reclamation via microbiome presents itself as an innovative and environmentally friendly option. Due to their low pathogenicity, endurance to adverse environmental conditions, and production of a wide variety of secondary metabolic compounds, members of the genus Streptomyces are good candidates for bio-reclamation of salt-affected soils. Thus, plant growth promotion and soil bioremediation strategies combine to overcome biotic and abiotic stressors, providing green management options for agriculture in the near future.
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Affiliation(s)
- Neli Romano-Armada
- Instituto de Investigaciones para la Industria Química (INIQUI), Universidad Nacional de Salta (UNSa)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Av. Bolivia 5150, Salta 4400, Argentina; (N.R.-A.); (M.F.Y.-Y.); (V.P.I.); (N.B.M.)
- Facultad de Ingeniería, UNSa, Salta 4400, Argentina
| | - María Florencia Yañez-Yazlle
- Instituto de Investigaciones para la Industria Química (INIQUI), Universidad Nacional de Salta (UNSa)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Av. Bolivia 5150, Salta 4400, Argentina; (N.R.-A.); (M.F.Y.-Y.); (V.P.I.); (N.B.M.)
- Facultad de Ciencias Naturales, UNSa, Salta 4400, Argentina
| | - Verónica P. Irazusta
- Instituto de Investigaciones para la Industria Química (INIQUI), Universidad Nacional de Salta (UNSa)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Av. Bolivia 5150, Salta 4400, Argentina; (N.R.-A.); (M.F.Y.-Y.); (V.P.I.); (N.B.M.)
- Facultad de Ciencias Naturales, UNSa, Salta 4400, Argentina
| | - Verónica B. Rajal
- Instituto de Investigaciones para la Industria Química (INIQUI), Universidad Nacional de Salta (UNSa)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Av. Bolivia 5150, Salta 4400, Argentina; (N.R.-A.); (M.F.Y.-Y.); (V.P.I.); (N.B.M.)
- Facultad de Ingeniería, UNSa, Salta 4400, Argentina
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), School of Biological Sciences, Nanyang Technological University, Singapore 639798, Singapore
| | - Norma B. Moraga
- Instituto de Investigaciones para la Industria Química (INIQUI), Universidad Nacional de Salta (UNSa)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Av. Bolivia 5150, Salta 4400, Argentina; (N.R.-A.); (M.F.Y.-Y.); (V.P.I.); (N.B.M.)
- Facultad de Ingeniería, UNSa, Salta 4400, Argentina
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9
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Stiles BG. Clostridial Binary Toxins: Basic Understandings that Include Cell Surface Binding and an Internal "Coup de Grâce". Curr Top Microbiol Immunol 2019; 406:135-162. [PMID: 27380267 DOI: 10.1007/82_2016_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Clostridium species can make a remarkable number of different protein toxins, causing many diverse diseases in humans and animals. The binary toxins of Clostridium botulinum, C. difficile, C. perfringens, and C. spiroforme are one group of enteric-acting toxins that attack the actin cytoskeleton of various cell types. These enterotoxins consist of A (enzymatic) and B (cell binding/membrane translocation) components that assemble on the targeted cell surface or in solution, forming a multimeric complex. Once translocated into the cytosol via endosomal trafficking and acidification, the A component dismantles the filamentous actin-based cytoskeleton via mono-ADP-ribosylation of globular actin. Knowledge of cell surface receptors and how these usurped, host-derived molecules facilitate intoxication can lead to novel ways of defending against these clostridial binary toxins. A molecular-based understanding of the various steps involved in toxin internalization can also unveil therapeutic intervention points that stop the intoxication process. Furthermore, using these bacterial proteins as medicinal shuttle systems into cells provides intriguing possibilities in the future. The pertinent past and state-of-the-art present, regarding clostridial binary toxins, will be evident in this chapter.
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Affiliation(s)
- Bradley G Stiles
- Biology Department, Wilson College, Chambersburg, PA, 17201, USA.
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van der Aart LT, Spijksma GK, Harms A, Vollmer W, Hankemeier T, van Wezel GP. High-Resolution Analysis of the Peptidoglycan Composition in Streptomyces coelicolor. J Bacteriol 2018; 200:e00290-18. [PMID: 30061355 PMCID: PMC6153666 DOI: 10.1128/jb.00290-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/27/2018] [Indexed: 11/20/2022] Open
Abstract
The bacterial cell wall maintains cell shape and protects against bursting by turgor. A major constituent of the cell wall is peptidoglycan (PG), which is continuously modified to enable cell growth and differentiation through the concerted activity of biosynthetic and hydrolytic enzymes. Streptomycetes are Gram-positive bacteria with a complex multicellular life style alternating between mycelial growth and the formation of reproductive spores. This involves cell wall remodeling at apical sites of the hyphae during cell elongation and autolytic degradation of the vegetative mycelium during the onset of development and antibiotic production. Here, we show that there are distinct differences in the cross-linking and maturation of the PGs between exponentially growing vegetative hyphae and the aerial hyphae that undergo sporulation. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis identified over 80 different muropeptides, revealing that major PG hydrolysis takes place over the course of mycelial growth. Half of the dimers lacked one of the disaccharide units in transition-phase cells, most likely due to autolytic activity. The deacetylation of MurNAc to MurN was particularly pronounced in spores and strongly reduced in sporulation mutants with a deletion of bldD or whiG, suggesting that MurN is developmentally regulated. Altogether, our work highlights the dynamic and growth phase-dependent changes in the composition of the PG in StreptomycesIMPORTANCE Streptomycetes are bacteria with a complex lifestyle and are model organisms for bacterial multicellularity. From a single spore, a large multigenomic multicellular mycelium is formed, which differentiates to form spores. Programmed cell death is an important event during the onset of morphological differentiation. In this work, we provide new insights into the changes in the peptidoglycan composition and over time, highlighting changes over the course of development and between growing mycelia and spores. This revealed dynamic changes in the peptidoglycan when the mycelia aged, with extensive peptidoglycan hydrolysis and, in particular, an increase in the proportion of 3-3 cross-links. Additionally, we identified a muropeptide that accumulates predominantly in the spores and may provide clues toward spore development.
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Affiliation(s)
- Lizah T van der Aart
- Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Gerwin K Spijksma
- Division of Analytical Biosciences, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands
| | - Amy Harms
- Division of Analytical Biosciences, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Thomas Hankemeier
- Division of Analytical Biosciences, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands
| | - Gilles P van Wezel
- Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
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Morphology of Helicobacter pylori as a result of peptidoglycan and cytoskeleton rearrangements. GASTROENTEROLOGY REVIEW 2018; 13:182-195. [PMID: 30302161 PMCID: PMC6173076 DOI: 10.5114/pg.2018.78284] [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] [Received: 02/01/2018] [Accepted: 06/25/2018] [Indexed: 12/19/2022]
Abstract
Helicobacter pylori is a Gram-negative, microaerophilic bacterium colonising the gastric mucosa. Normally, this bacterium has a spiral shape, which is crucial for proper colonisation of the stomach and cork-screwing penetration of dense mucin covering this organ. However, H. pylori may also form curved/straight rods, filamentous forms and coccoid forms. This morphological variability affects nutrient transport and respiration processes, as well as motility, the ability to form aggregates/biofilms, and resistance to adverse environmental factors. For this reason, a more accurate understanding of the molecular determinants that control the morphology of H. pylori seems to be crucial in increasing the effectiveness of antibacterial therapies directed against this microorganism. This article focuses on the molecular factors responsible for peptidoglycan and cytoskeleton rearrangements affecting H. pylori morphology and survivability. In addition, the existence of proteins associated with modifications of H. pylori morphology as potential targets in therapies reducing the virulence of this bacterium has been suggested.
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12
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Kim KW. Prokaryotic cytoskeletons: in situ and ex situ structures and cellular locations. Antonie van Leeuwenhoek 2018; 112:145-157. [PMID: 30128891 DOI: 10.1007/s10482-018-1142-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 08/11/2018] [Indexed: 01/12/2023]
Abstract
Cytoskeletons have long been perceived to be present only in eukaryotes. However, this notion changed drastically in the 1990s, with observations of cytoskeleton-like structures in several prokaryotes. Homologs of the main components of eukaryotic cytoskeletons, such as microtubules, microfilaments, and intermediate filaments, have been identified in bacteria and archaea. Tubulin homologs include filamenting temperature-sensitive mutant Z (FtsZ), bacterial tubulin A/B (BtubA/B), and tubulin/FtsZ-like protein (TubZ), whereas actin homologs comprise murein region B (MreB) and crenactin. Unlike other proteins, crescentin (CreS) is a homolog of intermediate filaments. Recent findings elucidated their localization, structural organization, and helical properties in prokaryotes, thus revising traditional models. FtsZ is involved in cell division, forming a bundle of overlapping filaments that cover the entire division plane. Cryogenic transmission electron microscopy identified tubular structures of BtubA/B that were not previously identified using conventional ultrathin plastic sections. TubZ generates two joint filaments to form a quadruplex structure. After a long debate, MreB, a cell shape determinant, was shown to form filament stretches that move circumferentially around rod-shaped bacteria. Initially characterized as single-stranded, crenactin was eventually identified as right-handed double-stranded helical filaments. CreS, another cell shape determinant, forms filament bundles located inside the inner membrane of the concave side of cells. These observations suggest that the use of in situ or ex situ microscopy in combination with structural analysis techniques will enable the elucidation and further understanding of the current models of prokaryotic cytoskeletons.
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Affiliation(s)
- Ki Woo Kim
- School of Ecology and Environmental System, Kyungpook National University, Sangju, 37224, Korea. .,Tree Diagnostic Center, Kyungpook National University, Sangju, 37224, Korea.
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Sugitani K, Kohama T, Mimura K, Takeuchi M, Senda R, Morimoto H. Speciation of Paleoarchean Life Demonstrated by Analysis of the Morphological Variation of Lenticular Microfossils from the Pilbara Craton, Australia. ASTROBIOLOGY 2018; 18:1057-1070. [PMID: 30070903 DOI: 10.1089/ast.2017.1799] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The ca 3.4 Ga Strelley Pool Formation (SPF) of the Pilbara Craton, Australia, represents a Paleoarchean sedimentary succession preserving well-described and morphologically diverse biosignatures such as stromatolites and cellularly preserved microfossils. The SPF microfossil assemblage identified from three greenstone belts includes relatively large (20-80 μm in width), acid-resistant, organic-walled lenticular microfossils, which can be extracted using a palynological technique. In this study, we present results of measurements of over 800 palynomorphic specimens of SPF lenticular microfossils from 2 remote (∼80 km apart) localities that represent different depositional environments and thus different habitats, as evidenced by their distinct lithostratigraphic association and trace element geochemistry. We demonstrate statistically that the two populations are distinct in oblateness from a polar view and furthermore that each population comprises subpopulations defined by different areas and oblateness. This study may provide the earliest morphological evidence for speciation of unicellular organisms, which could have been allopatric (geographic) and adaptive. It can also be suggested that SPF lenticular microbes had highly organized cytoskeleton indispensable for strict control of the cell morphology of large and robust microbes, which in turn were likely advantageous to their prosperity and diversification.
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Affiliation(s)
- Kenichiro Sugitani
- 1 Department of Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University , Nagoya, Japan
| | - Takashi Kohama
- 1 Department of Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University , Nagoya, Japan
| | - Koichi Mimura
- 1 Department of Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University , Nagoya, Japan
| | - Makoto Takeuchi
- 1 Department of Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University , Nagoya, Japan
| | - Ryoko Senda
- 2 Japan Agency for Marine-Earth Science and Technology , Yokosuka, Japan
| | - Hiroshi Morimoto
- 1 Department of Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University , Nagoya, Japan
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Sporulation-specific cell division defects in ylmE mutants of Streptomyces coelicolor are rescued by additional deletion of ylmD. Sci Rep 2018; 8:7328. [PMID: 29743540 PMCID: PMC5943314 DOI: 10.1038/s41598-018-25782-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/25/2018] [Indexed: 01/15/2023] Open
Abstract
Cell division during the reproductive phase of the Streptomyces life-cycle requires tight coordination between synchronous formation of multiple septa and DNA segregation. One remarkable difference with most other bacterial systems is that cell division in Streptomyces is positively controlled by the recruitment of FtsZ by SsgB. Here we show that deletion of ylmD (SCO2081) or ylmE (SCO2080), which lie in operon with ftsZ in the dcw cluster of actinomycetes, has major consequences for sporulation-specific cell division in Streptomyces coelicolor. Electron and fluorescence microscopy demonstrated that ylmE mutants have a highly aberrant phenotype with defective septum synthesis, and produce very few spores with low viability and high heat sensitivity. FtsZ-ring formation was also highly disturbed in ylmE mutants. Deletion of ylmD had a far less severe effect on sporulation. Interestingly, the additional deletion of ylmD restored sporulation to the ylmE null mutant. YlmD and YlmE are not part of the divisome, but instead localize diffusely in aerial hyphae, with differential intensity throughout the sporogenic part of the hyphae. Taken together, our work reveals a function for YlmD and YlmE in the control of sporulation-specific cell division in S. coelicolor, whereby the presence of YlmD alone results in major developmental defects.
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15
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Otten C, Brilli M, Vollmer W, Viollier PH, Salje J. Peptidoglycan in obligate intracellular bacteria. Mol Microbiol 2018; 107:142-163. [PMID: 29178391 PMCID: PMC5814848 DOI: 10.1111/mmi.13880] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2017] [Indexed: 01/08/2023]
Abstract
Peptidoglycan is the predominant stress-bearing structure in the cell envelope of most bacteria, and also a potent stimulator of the eukaryotic immune system. Obligate intracellular bacteria replicate exclusively within the interior of living cells, an osmotically protected niche. Under these conditions peptidoglycan is not necessarily needed to maintain the integrity of the bacterial cell. Moreover, the presence of peptidoglycan puts bacteria at risk of detection and destruction by host peptidoglycan recognition factors and downstream effectors. This has resulted in a selective pressure and opportunity to reduce the levels of peptidoglycan. In this review we have analysed the occurrence of genes involved in peptidoglycan metabolism across the major obligate intracellular bacterial species. From this comparative analysis, we have identified a group of predicted 'peptidoglycan-intermediate' organisms that includes the Chlamydiae, Orientia tsutsugamushi, Wolbachia and Anaplasma marginale. This grouping is likely to reflect biological differences in their infection cycle compared with peptidoglycan-negative obligate intracellular bacteria such as Ehrlichia and Anaplasma phagocytophilum, as well as obligate intracellular bacteria with classical peptidoglycan such as Coxiella, Buchnera and members of the Rickettsia genus. The signature gene set of the peptidoglycan-intermediate group reveals insights into minimal enzymatic requirements for building a peptidoglycan-like sacculus and/or division septum.
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Affiliation(s)
- Christian Otten
- The Centre for Bacterial Cell BiologyInstitute for Cell and Molecular Biosciences, Newcastle UniversityNewcastle upon TyneNE2 4AXUK
| | - Matteo Brilli
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE)University of Padova. Agripolis ‐ V.le dell'Università, 16 | 35020 Legnaro PadovaItaly
- Present address:
Department of BiosciencesUniversity of Milan, via Celoria 26(MI)Italy
| | - Waldemar Vollmer
- The Centre for Bacterial Cell BiologyInstitute for Cell and Molecular Biosciences, Newcastle UniversityNewcastle upon TyneNE2 4AXUK
| | - Patrick H. Viollier
- Department of Microbiology and Molecular MedicineInstitute of Genetics & Genomics in Geneva (iGE3), University of GenevaGenevaSwitzerland
| | - Jeanne Salje
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global HealthUniversity of OxfordOxfordUK
- Mahidol‐Oxford Tropical Medicine Research UnitMahidol UniversityBangkokThailand
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16
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Shin SM, Song SH, Lee JW, Kwak MK, Kang SO. Methylglyoxal synthase regulates cell elongation via alterations of cellular methylglyoxal and spermidine content in Bacillus subtilis. Int J Biochem Cell Biol 2017; 91:14-28. [PMID: 28807600 DOI: 10.1016/j.biocel.2017.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/14/2017] [Accepted: 08/08/2017] [Indexed: 01/03/2023]
Abstract
Methylglyoxal regulates cell division and differentiation through its interaction with polyamines. Loss of their biosynthesizing enzyme causes physiological impairment and cell elongation in eukaryotes. However, the reciprocal effects of methylglyoxal and polyamine production and its regulatory metabolic switches on morphological changes in prokaryotes have not been addressed. Here, Bacillus subtilis methylglyoxal synthase (mgsA) and polyamine biosynthesizing genes encoding arginine decarboxylase (SpeA), agmatinase (SpeB), and spermidine synthase (SpeE), were disrupted or overexpressed. Treatment of 0.2mM methylglyoxal and 1mM spermidine led to the elongation and shortening of B. subtilis wild-type cells to 12.38±3.21μm (P<0.05) and 3.24±0.73μm (P<0.01), respectively, compared to untreated cells (5.72±0.68μm). mgsA-deficient (mgsA-) and -overexpressing (mgsAOE) mutants also demonstrated cell shortening and elongation, similar to speB- and speE-deficient (speB- and speE-) and -overexpressing (speBOE and speEOE) mutants. Importantly, both mgsA-depleted speBOE and speEOE mutants (speBOE/mgsA- and speEOE/mgsA-) were drastically shortened to 24.5% and 23.8% of parental speBOE and speEOE mutants, respectively. These phenotypes were associated with reciprocal alterations of mgsA and polyamine transcripts governed by the contents of methylglyoxal and spermidine, which are involved in enzymatic or genetic metabolite-control mechanisms. Additionally, biophysically detected methylglyoxal-spermidine Schiff bases did not affect morphogenesis. Taken together, the findings indicate that methylglyoxal triggers cell elongation. Furthermore, cells with methylglyoxal accumulation commonly exhibit an elongated rod-shaped morphology through upregulation of mgsA, polyamine genes, and the global regulator spx, as well as repression of the cell division and shape regulator, FtsZ.
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Affiliation(s)
- Sang-Min Shin
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Sung-Hyun Song
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Jin-Woo Lee
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Min-Kyu Kwak
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
| | - Sa-Ouk Kang
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
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17
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Three-Dimensional Structure of the Ultraoligotrophic Marine Bacterium "Candidatus Pelagibacter ubique". Appl Environ Microbiol 2017; 83:AEM.02807-16. [PMID: 27836840 DOI: 10.1128/aem.02807-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 11/09/2016] [Indexed: 11/20/2022] Open
Abstract
SAR11 bacteria are small, heterotrophic, marine alphaproteobacteria found throughout the oceans. They thrive at the low nutrient concentrations typical of open ocean conditions, although the adaptations required for life under those conditions are not well understood. To illuminate this issue, we used cryo-electron tomography to study "Candidatus Pelagibacter ubique" strain HTCC1062, a member of the SAR11 clade. Our results revealed its cellular dimensions and details of its intracellular organization. Frozen-hydrated cells, which were preserved in a life-like state, had an average cell volume (enclosed by the outer membrane) of 0.037 ± 0.011 μm3 Strikingly, the periplasmic space occupied ∼20% to 50% of the total cell volume in log-phase cells and ∼50% to 70% in stationary-phase cells. The nucleoid occupied the convex side of the crescent-shaped cells and the ribosomes predominantly occupied the concave side, at a relatively high concentration of 10,000 to 12,000 ribosomes/μm3 Outer membrane pore complexes, likely composed of PilQ, were frequently observed in both log-phase and stationary-phase cells. Long filaments, most likely type IV pili, were found on dividing cells. The physical dimensions, intracellular organization, and morphological changes throughout the life cycle of "Ca. Pelagibacter ubique" provide structural insights into the functional adaptions of these oligotrophic ultramicrobacteria to their habitat. IMPORTANCE Bacterioplankton of the SAR11 clade (Pelagibacterales) are of interest because of their global biogeochemical significance and because they appear to have been molded by unusual evolutionary circumstances that favor simplicity and efficiency. They have adapted to an ecosystem in which nutrient concentrations are near the extreme limits at which transport systems can function adequately, and they have evolved streamlined genomes to execute only functions essential for life. However, little is known about the actual size limitations and cellular features of living oligotrophic ultramicrobacteria. In this study, we have used cryo-electron tomography to obtain accurate physical information about the cellular architecture of "Candidatus Pelagibacter ubique," the first cultivated member of the SAR11 clade. These results provide foundational information for answering questions about the cell architecture and functions of these ultrasmall oligotrophic bacteria.
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18
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Vélez M. Dynamic and Active Proteins: Biomolecular Motors in Engineered Nanostructures. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 940:121-141. [DOI: 10.1007/978-3-319-39196-0_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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19
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Cross-membranes orchestrate compartmentalization and morphogenesis in Streptomyces. Nat Commun 2016; 7:ncomms11836. [PMID: 27291257 PMCID: PMC4909990 DOI: 10.1038/ncomms11836] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 05/05/2016] [Indexed: 11/16/2022] Open
Abstract
Far from being simple unicellular entities, bacteria have complex social behaviour and organization, living in large populations, and some even as coherent, multicellular entities. The filamentous streptomycetes epitomize such multicellularity, growing as a syncytial mycelium with physiologically distinct hyphal compartments separated by infrequent cross-walls. The viability of mutants devoid of cell division, which can be propagated from fragments, suggests the presence of a different form of compartmentalization in the mycelium. Here we show that complex membranes, visualized by cryo-correlative light microscopy and electron tomography, fulfil this role. Membranes form small assemblies between the cell wall and cytoplasmic membrane, or, as evidenced by FRAP experiments, large protein-impermeable cross-membrane structures, which compartmentalize the multinucleoid mycelium. All areas containing cross-membrane structures are nucleoid-restricted zones, suggesting that the membrane assemblies may also act to protect nucleoids from cell-wall restructuring events. Our work reveals a novel mechanism of controlling compartmentalization and development in multicellular bacteria. Streptomycetes are multicellular bacteria that grow as multinucleoid filaments with infrequent cross-walls. Here, the authors describe a membrane system that forms protein-impermeable barriers and compartmentalizes the multinucleoid filaments independently from the FtsZ-guided cell division machinery.
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20
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Koonin EV. Origin of eukaryotes from within archaea, archaeal eukaryome and bursts of gene gain: eukaryogenesis just made easier? Philos Trans R Soc Lond B Biol Sci 2016; 370:20140333. [PMID: 26323764 PMCID: PMC4571572 DOI: 10.1098/rstb.2014.0333] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The origin of eukaryotes is a fundamental, forbidding evolutionary puzzle. Comparative genomic analysis clearly shows that the last eukaryotic common ancestor (LECA) possessed most of the signature complex features of modern eukaryotic cells, in particular the mitochondria, the endomembrane system including the nucleus, an advanced cytoskeleton and the ubiquitin network. Numerous duplications of ancestral genes, e.g. DNA polymerases, RNA polymerases and proteasome subunits, also can be traced back to the LECA. Thus, the LECA was not a primitive organism and its emergence must have resulted from extensive evolution towards cellular complexity. However, the scenario of eukaryogenesis, and in particular the relationship between endosymbiosis and the origin of eukaryotes, is far from being clear. Four recent developments provide new clues to the likely routes of eukaryogenesis. First, evolutionary reconstructions suggest complex ancestors for most of the major groups of archaea, with the subsequent evolution dominated by gene loss. Second, homologues of signature eukaryotic proteins, such as actin and tubulin that form the core of the cytoskeleton or the ubiquitin system, have been detected in diverse archaea. The discovery of this ‘dispersed eukaryome’ implies that the archaeal ancestor of eukaryotes was a complex cell that might have been capable of a primitive form of phagocytosis and thus conducive to endosymbiont capture. Third, phylogenomic analyses converge on the origin of most eukaryotic genes of archaeal descent from within the archaeal evolutionary tree, specifically, the TACK superphylum. Fourth, evidence has been presented that the origin of the major archaeal phyla involved massive acquisition of bacterial genes. Taken together, these findings make the symbiogenetic scenario for the origin of eukaryotes considerably more plausible and the origin of the organizational complexity of eukaryotic cells more readily explainable than they appeared until recently.
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Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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21
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Characterization of the in vitro assembly of FtsZ in Arthrobacter strain A3 using light scattering. Int J Biol Macromol 2016; 91:294-8. [PMID: 27164494 DOI: 10.1016/j.ijbiomac.2016.04.090] [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: 03/24/2016] [Revised: 04/27/2016] [Accepted: 04/28/2016] [Indexed: 12/16/2022]
Abstract
The self-assembly of FtsZ, the bacterial homolog of tubulin, plays an essential role in cell division. Light scattering technique is applied to real-time monitor the in vitro assembly of FtsZ in Arthrobacter strain A3, a newly isolated psychrotrophic bacterium. The critical concentration needed for the assembly is estimated as 6.7μM. The polymerization of FtsZ in Arthrobacter strain A3 requires both GTP and divalent metal ions, while salt is an unfavorable condition for the assembly. The FtsZ polymerizes under a wide range of pHs, with the fastest rate around pH 6.0. The FtsZ from Arthrobacter strain A3 resembles Mycobacterium tuberculosis FtsZ in terms of the dependence on divalent metal ions and the slow polymerization rate, while it is different from M. tuberculosis FtsZ considering the sensitivity to salt and pH. The comparison of FtsZ from different organisms will greatly advance our understanding of the biological role of the key cell division protein.
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22
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Barka EA, Vatsa P, Sanchez L, Gaveau-Vaillant N, Jacquard C, Meier-Kolthoff JP, Klenk HP, Clément C, Ouhdouch Y, van Wezel GP. Taxonomy, Physiology, and Natural Products of Actinobacteria. Microbiol Mol Biol Rev 2016; 80:1-43. [PMID: 26609051 PMCID: PMC4711186 DOI: 10.1128/mmbr.00019-15] [Citation(s) in RCA: 896] [Impact Index Per Article: 112.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Actinobacteria are Gram-positive bacteria with high G+C DNA content that constitute one of the largest bacterial phyla, and they are ubiquitously distributed in both aquatic and terrestrial ecosystems. Many Actinobacteria have a mycelial lifestyle and undergo complex morphological differentiation. They also have an extensive secondary metabolism and produce about two-thirds of all naturally derived antibiotics in current clinical use, as well as many anticancer, anthelmintic, and antifungal compounds. Consequently, these bacteria are of major importance for biotechnology, medicine, and agriculture. Actinobacteria play diverse roles in their associations with various higher organisms, since their members have adopted different lifestyles, and the phylum includes pathogens (notably, species of Corynebacterium, Mycobacterium, Nocardia, Propionibacterium, and Tropheryma), soil inhabitants (e.g., Micromonospora and Streptomyces species), plant commensals (e.g., Frankia spp.), and gastrointestinal commensals (Bifidobacterium spp.). Actinobacteria also play an important role as symbionts and as pathogens in plant-associated microbial communities. This review presents an update on the biology of this important bacterial phylum.
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Affiliation(s)
- Essaid Ait Barka
- Laboratoire de Stress, Défenses et Reproduction des Plantes, Unité de Recherche Vignes et Vins de Champagne, UFR Sciences, UPRES EA 4707, Université de Reims Champagne-Ardenne, Reims, France
| | - Parul Vatsa
- Laboratoire de Stress, Défenses et Reproduction des Plantes, Unité de Recherche Vignes et Vins de Champagne, UFR Sciences, UPRES EA 4707, Université de Reims Champagne-Ardenne, Reims, France
| | - Lisa Sanchez
- Laboratoire de Stress, Défenses et Reproduction des Plantes, Unité de Recherche Vignes et Vins de Champagne, UFR Sciences, UPRES EA 4707, Université de Reims Champagne-Ardenne, Reims, France
| | - Nathalie Gaveau-Vaillant
- Laboratoire de Stress, Défenses et Reproduction des Plantes, Unité de Recherche Vignes et Vins de Champagne, UFR Sciences, UPRES EA 4707, Université de Reims Champagne-Ardenne, Reims, France
| | - Cedric Jacquard
- Laboratoire de Stress, Défenses et Reproduction des Plantes, Unité de Recherche Vignes et Vins de Champagne, UFR Sciences, UPRES EA 4707, Université de Reims Champagne-Ardenne, Reims, France
| | | | - Hans-Peter Klenk
- School of Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Christophe Clément
- Laboratoire de Stress, Défenses et Reproduction des Plantes, Unité de Recherche Vignes et Vins de Champagne, UFR Sciences, UPRES EA 4707, Université de Reims Champagne-Ardenne, Reims, France
| | - Yder Ouhdouch
- Faculté de Sciences Semlalia, Université Cadi Ayyad, Laboratoire de Biologie et de Biotechnologie des Microorganismes, Marrakesh, Morocco
| | - Gilles P van Wezel
- Molecular Biotechnology, Institute of Biology, Sylvius Laboratories, Leiden University, Leiden, The Netherlands
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23
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Abstract
Traditionally eukaryotes exclusive cytoskeleton has been found in bacteria and other prokaryotes. FtsZ, MreB and CreS are bacterial counterpart of eukaryotic tubulin, actin filaments and intermediate filaments, respectively. FtsZ can assemble to a Z-ring at the cell division site, regulate bacterial cell division; MreB can form helical structure, and involve in maintaining cell shape, regulating chromosome segregation; CreS, found in Caulobacter crescentus (C. crescentus), can form curve or helical filaments in intracellular membrane. CreS is crucial for cell morphology maintenance. There are also some prokaryotic unique cytoskeleton components playing crucial roles in cell division, chromosome segregation and cell morphology. The cytoskeleton components of Mycobacterium tuberculosis (M. tuberculosis), together with their dynamics during exposure to antibiotics are summarized in this article to provide insights into the unique organization of this formidable pathogen and druggable targets for new antibiotics.
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Affiliation(s)
- Huan Wang
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| | - Longxiang Xie
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| | - Hongping Luo
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
| | - Jianping Xie
- a Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University , Chongqing , China
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24
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Zuckerman DM, Boucher LE, Xie K, Engelhardt H, Bosch J, Hoiczyk E. The bactofilin cytoskeleton protein BacM of Myxococcus xanthus forms an extended β-sheet structure likely mediated by hydrophobic interactions. PLoS One 2015; 10:e0121074. [PMID: 25803609 PMCID: PMC4372379 DOI: 10.1371/journal.pone.0121074] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 01/29/2015] [Indexed: 11/18/2022] Open
Abstract
Bactofilins are novel cytoskeleton proteins that are widespread in Gram-negative bacteria. Myxococcus xanthus, an important predatory soil bacterium, possesses four bactofilins of which one, BacM (Mxan_7475) plays an important role in cell shape maintenance. Electron and fluorescence light microscopy, as well as studies using over-expressed, purified BacM, indicate that this protein polymerizes in vivo and in vitro into ~3 nm wide filaments that further associate into higher ordered fibers of about 10 nm. Here we use a multipronged approach combining secondary structure determination, molecular modeling, biochemistry, and genetics to identify and characterize critical molecular elements that enable BacM to polymerize. Our results indicate that the bactofilin-determining domain DUF583 folds into an extended β-sheet structure, and we hypothesize a left-handed β-helix with polymerization into 3 nm filaments primarily via patches of hydrophobic amino acid residues. These patches form the interface allowing head-to-tail polymerization during filament formation. Biochemical analyses of these processes show that folding and polymerization occur across a wide variety of conditions and even in the presence of chaotropic agents such as one molar urea. Together, these data suggest that bactofilins are comprised of a structure unique to cytoskeleton proteins, which enables robust polymerization.
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Affiliation(s)
- David M. Zuckerman
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Lauren E. Boucher
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute, Baltimore, Maryland, United States of America
| | - Kefang Xie
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Harald Engelhardt
- Department of Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Germany
| | - Jürgen Bosch
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health and Johns Hopkins Malaria Research Institute, Baltimore, Maryland, United States of America
| | - Egbert Hoiczyk
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail:
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25
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Wu H, Iwai N, Nakano T, Ooi Y, Ishihara S, Sano K. Route of intrabacterial nanotransportation system for CagA in Helicobacter pylori. Med Mol Morphol 2015; 48:191-203. [PMID: 25707504 DOI: 10.1007/s00795-015-0097-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 02/05/2015] [Indexed: 12/11/2022]
Abstract
Helicobacter pylori (H. pylori) possesses an intrabacterial nanotransportation system (ibNoTS) for transporting CagA and urease within the bacterial cytoplasm; this system is controlled by the extrabacterial environment. The transportation routes of the system have not yet been studied in detail. In this study, we demonstrated by immunoelectron microscopy that CagA localizes closely with the MreB filament in the bacterium, and MreB polymerization inhibitor A22 obstructs ibNoTS for CagA. These findings indicate that the route of ibNoTS for CagA is closely associated with the MreB filament. Because these phenomena were not observed in ibNoTS for urease, the route of ibNoTS for CagA is different from that of ibNoTS for urease as previously suggested. We propose that the route of ibNoTS for CagA is associated with the MreB filament in H. pylori.
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Affiliation(s)
- Hong Wu
- Project Team for Study of Nanotransportation System, Central Research Center, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan. .,Department of Microbiology and Infection Control, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan.
| | - Noritaka Iwai
- Project Team for Study of Nanotransportation System, Central Research Center, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan.,Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa, 226-8501, Japan
| | - Takashi Nakano
- Project Team for Study of Nanotransportation System, Central Research Center, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan.,Department of Microbiology and Infection Control, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan
| | - Yukimasa Ooi
- Department of Microbiology and Infection Control, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan.,Infection Control Office, Osaka Medical College Hospital, Osaka, Japan
| | - Sonoko Ishihara
- Department of Microbiology and Infection Control, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan
| | - Kouichi Sano
- Project Team for Study of Nanotransportation System, Central Research Center, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan.,Department of Microbiology and Infection Control, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka, 569-8686, Japan
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26
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The Cellular Chassis as the Basis for New Functionalities: Shortcomings and Requirements. Synth Biol (Oxf) 2015. [DOI: 10.1007/978-3-319-02783-8_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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27
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Tuson HH, Biteen JS. Unveiling the inner workings of live bacteria using super-resolution microscopy. Anal Chem 2014; 87:42-63. [PMID: 25380480 DOI: 10.1021/ac5041346] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Hannah H Tuson
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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28
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van Dissel D, Claessen D, van Wezel GP. Morphogenesis of Streptomyces in submerged cultures. ADVANCES IN APPLIED MICROBIOLOGY 2014; 89:1-45. [PMID: 25131399 DOI: 10.1016/b978-0-12-800259-9.00001-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Members of the genus Streptomyces are mycelial bacteria that undergo a complex multicellular life cycle and propagate via sporulation. Streptomycetes are important industrial microorganisms, as they produce a plethora of medically relevant natural products, including the majority of clinically important antibiotics, as well as a wide range of enzymes with industrial application. While development of Streptomyces in surface-grown cultures is well studied, relatively little is known of the parameters that determine morphogenesis in submerged cultures. Here, growth is characterized by the formation of mycelial networks and pellets. From the perspective of industrial fermentations, such mycelial growth is unattractive, as it is associated with slow growth, heterogeneous cultures, and high viscosity. Here, we review the current insights into the genetic and environmental factors that determine mycelial growth and morphology in liquid-grown cultures. The genetic factors include cell-matrix proteins and extracellular polymers, morphoproteins with specific roles in liquid-culture morphogenesis, with the SsgA-like proteins as well-studied examples, and programmed cell death. Environmental factors refer in particular to those dictated by process engineering, such as growth media and reactor set-up. These insights are then integrated to provide perspectives as to how this knowledge can be applied to improve streptomycetes for industrial applications.
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Affiliation(s)
- Dino van Dissel
- Molecular Biotechnology, Institute Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Dennis Claessen
- Molecular Biotechnology, Institute Biology Leiden, Leiden University, Leiden, The Netherlands.
| | - Gilles P van Wezel
- Molecular Biotechnology, Institute Biology Leiden, Leiden University, Leiden, The Netherlands.
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Analysis of novel kitasatosporae reveals significant evolutionary changes in conserved developmental genes between Kitasatospora and Streptomyces. Antonie van Leeuwenhoek 2014; 106:365-80. [DOI: 10.1007/s10482-014-0209-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 05/30/2014] [Indexed: 12/17/2022]
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30
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Teng J, Loukin S, Anishkin A, Kung C. The force-from-lipid (FFL) principle of mechanosensitivity, at large and in elements. Pflugers Arch 2014; 467:27-37. [PMID: 24888690 DOI: 10.1007/s00424-014-1530-2] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 04/29/2014] [Accepted: 05/05/2014] [Indexed: 12/27/2022]
Abstract
Focus on touch and hearing distracts attention from numerous subconscious force sensors, such as the vital control of blood pressure and systemic osmolarity, and sensors in nonanimals. Multifarious manifestations should not obscure invariant and fundamental physicochemical principles. We advocate that force from lipid (FFL) is one such principle. It is based on the fact that the self-assembled bilayer necessitates inherent forces that are large and anisotropic, even at life's origin. Functional response of membrane proteins is governed by bilayer force changes. Added stress can redirect these forces, leading to geometric changes of embedded proteins such as ion channels. The FFL principle was first demonstrated when purified bacterial mechanosensitive channel of large conductance (MscL) remained mechanosensitive (MS) after reconstituting into bilayers. This key experiment has recently been unequivocally replicated with two vertebrate MS K2p channels. Even the canonical Kv and the Drosophila canonical transient receptor potentials (TRPCs) have now been shown to be MS in biophysical and in physiological contexts, supporting the universality of the FFL paradigm. We also review the deterministic role of mechanical force during stem cell differentiation as well as the cell-cell and cell-matrix tethers that provide force communications. In both the ear hair cell and the worm's touch neuron, deleting the cadherin or microtubule tethers reduces but does not eliminate MS channel activities. We found no evidence to distinguish whether these tethers directly pull on the channel protein or a surrounding lipid platform. Regardless of the implementation, pulling tether tenses up the bilayer. Membrane tenting is directly visible at the apexes of the stereocilia.
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Affiliation(s)
- Jinfeng Teng
- Laboratory of Molecular Biology, University of Wisconsin, Madison, WI, 53706, USA
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31
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Singh SP, Montgomery BL. Morphogenes bolA and mreB mediate the photoregulation of cellular morphology during complementary chromatic acclimation in Fremyella diplosiphon. Mol Microbiol 2014; 93:167-82. [PMID: 24823920 DOI: 10.1111/mmi.12649] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/12/2014] [Indexed: 11/29/2022]
Abstract
Photoregulation of pigmentation during complementary chromatic acclimation (CCA) is well studied in Fremyella diplosiphon; however, mechanistic insights into the CCA-associated morphological changes are still emerging. F. diplosiphon cells are rectangular under green light (GL), whereas cells are smaller and spherical under red light (RL). Here, we investigate the role of morphogenes bolA and mreB during CCA using gene expression and gene function analyses. The F. diplosiphon bolA gene is essential as its complete removal from the genome was unsuccessful. Depletion of bolA resulted in slow growth, morphological defects and the accumulation of high levels of reactive oxygen species in a partially segregated ΔbolA strain. Higher expression of bolA was observed under RL and was correlated with lower expression of mreB and mreC genes in wild type. In a ΔrcaE strain that lacks the red-/green-responsive RcaE photoreceptor, the expression of bolA and mre genes was altered under both RL and GL. Observed gene expression relationships suggest that mreB and mreC expression is controlled by RcaE-dependent photoregulation of bolA expression. Expression of F. diplosiphon bolA and mreB homologues in Escherichia coli demonstrated functional conservation of the encoded proteins. Together, these studies establish roles for bolA and mreB in RcaE-dependent regulation of cellular morphology.
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Affiliation(s)
- Shailendra P Singh
- Department of Energy - Plant Research Laboratory, Michigan State University, Plant Biology Laboratories, 612 Wilson Road, Room 106, East Lansing, MI, 48824-1312, USA
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Koonin EV, Yutin N. The dispersed archaeal eukaryome and the complex archaeal ancestor of eukaryotes. Cold Spring Harb Perspect Biol 2014; 6:a016188. [PMID: 24691961 DOI: 10.1101/cshperspect.a016188] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The ancestral set of eukaryotic genes is a chimera composed of genes of archaeal and bacterial origins thanks to the endosymbiosis event that gave rise to the mitochondria and apparently antedated the last common ancestor of the extant eukaryotes. The proto-mitochondrial endosymbiont is confidently identified as an α-proteobacterium. In contrast, the archaeal ancestor of eukaryotes remains elusive, although evidence is accumulating that it could have belonged to a deep lineage within the TACK (Thaumarchaeota, Aigarchaeota, Crenarchaeota, Korarchaeota) superphylum of the Archaea. Recent surveys of archaeal genomes show that the apparent ancestors of several key functional systems of eukaryotes, the components of the archaeal "eukaryome," such as ubiquitin signaling, RNA interference, and actin-based and tubulin-based cytoskeleton structures, are identifiable in different archaeal groups. We suggest that the archaeal ancestor of eukaryotes was a complex form, rooted deeply within the TACK superphylum, that already possessed some quintessential eukaryotic features, in particular, a cytoskeleton, and perhaps was capable of a primitive form of phagocytosis that would facilitate the engulfment of potential symbionts. This putative group of Archaea could have existed for a relatively short time before going extinct or undergoing genome streamlining, resulting in the dispersion of the eukaryome. This scenario might explain the difficulty with the identification of the archaeal ancestor of eukaryotes despite the straightforward detection of apparent ancestors to many signature eukaryotic functional systems.
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Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894
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Petersen RC. Computational conformational antimicrobial analysis developing mechanomolecular theory for polymer biomaterials in materials science and engineering. INTERNATIONAL JOURNAL OF COMPUTATIONAL MATERIALS SCIENCE AND ENGINEERING 2014; 3:1450003. [PMID: 25598972 PMCID: PMC4295723 DOI: 10.1142/s2047684114500031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Single-bond rotations or pyramidal inversions tend to either hide or expose relative energies that exist for atoms with nonbonding lone-pair electrons. Availability of lone-pair electrons depends on overall molecular electron distributions and differences in the immediate polarity of the surrounding pico/nanoenvironment. Stereochemistry three-dimensional aspects of molecules provide insight into conformations through single-bond rotations with associated lone-pair electrons on oxygen atoms in addition to pyramidal inversions with nitrogen atoms. When electrons are protected, potential energy is sheltered toward an energy minimum value to compatibilize molecularly with nonpolar environments. When electrons are exposed, maximum energy is available toward polar environment interactions. Computational conformational analysis software calculated energy profiles that exist during specific oxygen ether single-bond rotations with easy-to-visualize three-dimensional models for the trichlorinated bisaromatic ether triclosan antimicrobial polymer additive. As shown, fluctuating alternating bond rotations can produce complex interactions between molecules to provide entanglement strength for polymer toughness or alternatively disrupt weak secondary bonds of attraction to lower resin viscosity for new additive properties with nonpolar triclosan as a hydrophobic toughening/wetting agent. Further, bond rotations involving lone-pair electrons by a molecule at a nonpolar-hydrocarbon-membrane/polar-biologic-fluid interface might become sufficiently unstable to provide free mechanomolecular energies to disrupt weaker microbial membranes, for membrane transport of molecules into cells, provide cell signaling/recognition/defense and also generate enzyme mixing to speed reactions.
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Affiliation(s)
- Richard C Petersen
- Departments of Biomedical Engineering and Biomaterial Sciences University of Alabama at Birmingham, SDB 539, 1919 7th Avenue South Birmingham, Alabama 35294, USA
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Gahlmann A, Moerner WE. Exploring bacterial cell biology with single-molecule tracking and super-resolution imaging. Nat Rev Microbiol 2014; 12:9-22. [PMID: 24336182 DOI: 10.1038/nrmicro3154] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The ability to detect single molecules in live bacterial cells enables us to probe biological events one molecule at a time and thereby gain knowledge of the activities of intracellular molecules that remain obscure in conventional ensemble-averaged measurements. Single-molecule fluorescence tracking and super-resolution imaging are thus providing a new window into bacterial cells and facilitating the elucidation of cellular processes at an unprecedented level of sensitivity, specificity and spatial resolution. In this Review, we consider what these technologies have taught us about the bacterial cytoskeleton, nucleoid organization and the dynamic processes of transcription and translation, and we also highlight the methodological improvements that are needed to address a number of experimental challenges in the field.
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Affiliation(s)
- Andreas Gahlmann
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | - W E Moerner
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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Girard G, Traag BA, Sangal V, Mascini N, Hoskisson PA, Goodfellow M, van Wezel GP. A novel taxonomic marker that discriminates between morphologically complex actinomycetes. Open Biol 2013; 3:130073. [PMID: 24153003 PMCID: PMC3814722 DOI: 10.1098/rsob.130073] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In the era when large whole genome bacterial datasets are generated routinely, rapid and accurate molecular systematics is becoming increasingly important. However, 16S ribosomal RNA sequencing does not always offer sufficient resolution to discriminate between closely related genera. The SsgA-like proteins are developmental regulatory proteins in sporulating actinomycetes, whereby SsgB actively recruits FtsZ during sporulation-specific cell division. Here, we present a novel method to classify actinomycetes, based on the extraordinary way the SsgA and SsgB proteins are conserved. The almost complete conservation of the SsgB amino acid (aa) sequence between members of the same genus and its high divergence between even closely related genera provides high-quality data for the classification of morphologically complex actinomycetes. Our analysis validates Kitasatospora as a sister genus to Streptomyces in the family Streptomycetaceae and suggests that Micromonospora, Salinispora and Verrucosispora may represent different clades of the same genus. It is also apparent that the aa sequence of SsgA is an accurate determinant for the ability of streptomycetes to produce submerged spores, dividing the phylogenetic tree of streptomycetes into liquid-culture sporulation and no liquid-culture sporulation branches. A new phylogenetic tree of industrially relevant actinomycetes is presented and compared with that based on 16S rRNA sequences.
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Affiliation(s)
- Geneviève Girard
- Molecular Biotechnology, Institute of Biology, Leiden University, PO Box 9505, 2300 RA Leiden, The Netherlands
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Saier MH. Microcompartments and protein machines in prokaryotes. J Mol Microbiol Biotechnol 2013; 23:243-69. [PMID: 23920489 DOI: 10.1159/000351625] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The prokaryotic cell was once thought of as a 'bag of enzymes' with little or no intracellular compartmentalization. In this view, most reactions essential for life occurred as a consequence of random molecular collisions involving substrates, cofactors and cytoplasmic enzymes. Our current conception of a prokaryote is far from this view. We now consider a bacterium or an archaeon as a highly structured, nonrandom collection of functional membrane-embedded and proteinaceous molecular machines, each of which serves a specialized function. In this article we shall present an overview of such microcompartments including (1) the bacterial cytoskeleton and the apparati allowing DNA segregation during cell division; (2) energy transduction apparati involving light-driven proton pumping and ion gradient-driven ATP synthesis; (3) prokaryotic motility and taxis machines that mediate cell movements in response to gradients of chemicals and physical forces; (4) machines of protein folding, secretion and degradation; (5) metabolosomes carrying out specific chemical reactions; (6) 24-hour clocks allowing bacteria to coordinate their metabolic activities with the daily solar cycle, and (7) proteinaceous membrane compartmentalized structures such as sulfur granules and gas vacuoles. Membrane-bound prokaryotic organelles were considered in a recent Journal of Molecular Microbiology and Biotechnology written symposium concerned with membranous compartmentalization in bacteria [J Mol Microbiol Biotechnol 2013;23:1-192]. By contrast, in this symposium, we focus on proteinaceous microcompartments. These two symposia, taken together, provide the interested reader with an objective view of the remarkable complexity of what was once thought of as a simple noncompartmentalized cell.
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Affiliation(s)
- Milton H Saier
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, Calif. 92093-0116, USA.
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Celler K, van Wezel GP, Willemse J. Single particle tracking of dynamically localizing TatA complexes in Streptomyces coelicolor. Biochem Biophys Res Commun 2013; 438:38-42. [PMID: 23867823 DOI: 10.1016/j.bbrc.2013.07.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 07/03/2013] [Indexed: 01/17/2023]
Abstract
The Tat (twin-arginine translocation) pathway transports folded proteins across the bacterial cytoplasmic membrane and is a major route of protein export in the mycelial soil-dwelling bacterium Streptomyces. We recently examined the localization of Tat components (TatABC) in time-lapse imaging and demonstrated that all three components colocalize dynamically with a preference for apical sites. Here we apply an in-house single particle tracking package to quantitatively analyze the movement of the TatA subunit, the most abundant of the Tat components. Segmentation and analysis of trajectories revealed that TatA transitions from free to confined movement and then to fixed localization. The sequence starts with a mixed punctate and dispersed localization of TatA oligomers, which then develop into a few larger still foci, and finally colocalize with TatBC to form a functional translocation system. It takes 15-30 min for the Tat export complex to assemble and most likely become active. With this study we provide the first example of quantitative analysis of dynamic protein localization in Streptomyces, which is applicable to the study of many other dynamically localizing proteins identified in these complex bacteria.
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Affiliation(s)
- Katherine Celler
- Molecular Biotechnology, Institute of Biology Leiden, Sylvius Laboratories, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
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