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Tittes C, Nijland J, Schoentag AMC, Hackl T, Di Cianni N, Marchfelder A, Quax TEF. Development of a genetic system for Haloferax gibbonsii LR2-5, model host for haloarchaeal viruses. Appl Environ Microbiol 2024; 90:e0012924. [PMID: 38470030 PMCID: PMC11022537 DOI: 10.1128/aem.00129-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 02/20/2024] [Indexed: 03/13/2024] Open
Abstract
Archaeal viruses are among the most enigmatic members of the virosphere, and their diverse morphologies raise many questions about their infection mechanisms. The study of molecular mechanisms underlying virus-host interactions hinges upon robust model organisms with a system for gene expression and deletion. Currently, there are only a limited number of archaea that have associated viruses and have a well-developed genetic system. Here, we report the development of a genetic system for the euryarchaeon Haloferax gibbonsii LR2-5. This strain can be infected by multiple viruses and is a model for the study of virus-host interactions. We created a Hfx. gibbonsii LR2-5 ∆pyrE strain, resulting in uracil auxotrophy, which could be used as a selection marker. An expression plasmid carrying a pyrE gene from the well-established Haloferax volcanii system was tested for functionality. Expression of a GFP-MinD fusion under a tryptophan inducible promoter was fully functional and showed similar cellular localization as in Hfx. volcanii. Thus, the plasmids of the Hfx. volcanii system can be used directly for the Hfx. gibbonsii LR2-5 genetic system, facilitating the transfer of tools between the two. Finally, we tested for the functionality of gene deletions by knocking out two genes of the archaeal motility structure, the archaellum. These deletion mutants were as expected non-motile and the phenotype of one deletion could be rescued by the expression of the deleted archaellum gene from a plasmid. Thus, we developed a functional genetic toolbox for the euryarchaeal virus host Hfx. gibbonsii LR2-5, which will propel future studies on archaeal viruses. IMPORTANCE Species from all domains of life are infected by viruses. In some environments, viruses outnumber their microbial hosts by a factor of 10, and viruses are the most important predators of microorganisms. While much has been discovered about the infection mechanisms of bacterial and eukaryotic viruses, archaeal viruses remain understudied. Good model systems are needed to study their virus-host interactions in detail. The salt-loving archaeon Haloferax gibbonsii LR2-5 has been shown to be infected by a variety of different viruses and, thus, is an excellent model to study archaeal viruses. By establishing a genetic system, we have significantly expanded the toolbox for this model organism, which will fuel our understanding of infection strategies of the underexplored archaeal viruses.
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Affiliation(s)
- Colin Tittes
- Biology of Archaea and Viruses, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Jeroen Nijland
- Biology of Archaea and Viruses, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Anna M. C. Schoentag
- Biology of Archaea and Viruses, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Thomas Hackl
- Microbial Ecology Cluster, Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | | | | | - Tessa E. F. Quax
- Biology of Archaea and Viruses, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
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2
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Stöckl R, Nißl L, Reichelt R, Rachel R, Grohmann D, Grünberger F. The transcriptional regulator EarA and intergenic terminator sequences modulate archaellation in Pyrococcus furiosus. Front Microbiol 2023; 14:1241399. [PMID: 38029142 PMCID: PMC10665913 DOI: 10.3389/fmicb.2023.1241399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
The regulation of archaellation, the formation of archaeal-specific cell appendages called archaella, is crucial for the motility, adhesion, and survival of archaeal organisms. Although the heavily archaellated and highly motile Pyrococcus furiosus is a key model organism for understanding the production and function of archaella in Euryarchaea, the transcriptional regulation of archaellum assembly is so far unknown. Here we show that the transcription factor EarA is the master regulator of the archaellum (arl) operon transcription, which is further modulated by intergenic transcription termination signals. EarA deletion or overexpression strains demonstrate that EarA is essential for archaellation in P. furiosus and governs the degree of archaellation. Providing a single-molecule update on the transcriptional landscape of the arl operon in P. furiosus, we identify sequence motifs for EarA binding upstream of the arl operon and intergenic terminator sequences as critical elements for fine-tuning the expression of the multicistronic arl cluster. Furthermore, transcriptome re-analysis across different Thermococcales species demonstrated a heterogeneous production of major archaellins, suggesting a more diverse composition of archaella than previously recognized. Overall, our study provides novel insights into the transcriptional regulation of archaellation and highlights the essential role of EarA in Pyrococcus furiosus. These findings advance our understanding of the mechanisms governing archaellation and have implications for the functional diversity of archaella.
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Affiliation(s)
- Richard Stöckl
- Institute of Microbiology and Archaea Centre, Faculty for Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | - Laura Nißl
- Institute of Microbiology and Archaea Centre, Faculty for Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | - Robert Reichelt
- Institute of Microbiology and Archaea Centre, Faculty for Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | - Reinhard Rachel
- Centre for Electron Microscopy, Faculty for Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | - Dina Grohmann
- Institute of Microbiology and Archaea Centre, Faculty for Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
| | - Felix Grünberger
- Institute of Microbiology and Archaea Centre, Faculty for Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
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3
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Abstract
It has been suggested that a few methanogens are capable of extracellular electron transfers. For instance, Methanosarcina barkeri can directly capture electrons from the coexisting microbial cells of other species. Methanothrix harundinacea and Methanosarcina horonobensis retrieve electrons from Geobacter metallireducens via direct interspecies electron transfer (DIET). Recently, Methanobacterium, designated strain YSL, has been found to grow via DIET in the co-culture with Geobacter metallireducens. Methanosarcina acetivorans can perform anaerobic methane oxidation and respiratory growth relying on Fe(III) reduction through the extracellular electron transfer. Methanosarcina mazei is capable of electromethanogenesis under the conditions where electron-transfer mediators like H2 or formate are limited. The membrane-bound multiheme c-type cytochromes (MHC) and electrically-conductive cellular appendages have been assumed to mediate the extracellular electron transfer in bacteria like Geobacter and Shewanella species. These molecules or structures are rare but have been recently identified in a few methanogens. Here, we review the current state of knowledge for the putative extracellular electron transfers in methanogens and highlight the opportunities and challenges for future research.
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Affiliation(s)
- Kailin Gao
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yahai Lu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
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4
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Tittes C, Schwarzer S, Pfeiffer F, Dyall-Smith M, Rodriguez-Franco M, Oksanen HM, Quax TEF. Cellular and Genomic Properties of Haloferax gibbonsii LR2-5, the Host of Euryarchaeal Virus HFTV1. Front Microbiol 2021; 12:625599. [PMID: 33664716 PMCID: PMC7921747 DOI: 10.3389/fmicb.2021.625599] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/28/2021] [Indexed: 01/14/2023] Open
Abstract
Hypersaline environments are the source of many viruses infecting different species of halophilic euryarchaea. Information on infection mechanisms of archaeal viruses is scarce, due to the lack of genetically accessible virus–host models. Recently, a new archaeal siphovirus, Haloferax tailed virus 1 (HFTV1), was isolated together with its host belonging to the genus Haloferax, but it is not infectious on the widely used model euryarcheon Haloferax volcanii. To gain more insight into the biology of HFTV1 host strain LR2-5, we studied characteristics that might play a role in its virus susceptibility: growth-dependent motility, surface layer, filamentous surface structures, and cell shape. Its genome sequence showed that LR2-5 is a new strain of Haloferax gibbonsii. LR2-5 lacks obvious viral defense systems, such as CRISPR-Cas, and the composition of its cell surface is different from Hfx. volcanii, which might explain the different viral host range. This work provides first deep insights into the relationship between the host of halovirus HFTV1 and other members of the genus Haloferax. Given the close relationship to the genetically accessible Hfx. volcanii, LR2-5 has high potential as a new model for virus–host studies in euryarchaea.
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Affiliation(s)
- Colin Tittes
- Archaeal Virus-Host Interactions, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Sabine Schwarzer
- Archaeal Virus-Host Interactions, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Friedhelm Pfeiffer
- Computational Biology Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Mike Dyall-Smith
- Computational Biology Group, Max Planck Institute of Biochemistry, Martinsried, Germany.,Department of Veterinary Biosciences, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, Australia
| | | | - Hanna M Oksanen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Tessa E F Quax
- Archaeal Virus-Host Interactions, Faculty of Biology, University of Freiburg, Freiburg, Germany
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5
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Tittes C, Schwarzer S, Quax TEF. Viral Hijack of Filamentous Surface Structures in Archaea and Bacteria. Viruses 2021; 13:v13020164. [PMID: 33499367 PMCID: PMC7911016 DOI: 10.3390/v13020164] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/30/2022] Open
Abstract
The bacterial and archaeal cell surface is decorated with filamentous surface structures that are used for different functions, such as motility, DNA exchange and biofilm formation. Viruses hijack these structures and use them to ride to the cell surface for successful entry. In this review, we describe currently known mechanisms for viral attachment, translocation, and entry via filamentous surface structures. We describe the different mechanisms used to exploit various surface structures bacterial and archaeal viruses. This overview highlights the importance of filamentous structures at the cell surface for entry of prokaryotic viruses.
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6
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Schwarzer S, Rodriguez-Franco M, Oksanen HM, Quax TEF. Growth Phase Dependent Cell Shape of Haloarcula. Microorganisms 2021; 9:231. [PMID: 33499340 PMCID: PMC7911496 DOI: 10.3390/microorganisms9020231] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 01/08/2023] Open
Abstract
Several haloarchaea are reported to be pleomorphic, while others exhibit remarkable shapes, such as squares. Recently, Haloferax volcanii was found to alter its morphology during growth. Cells are motile rods in early exponential phase, and immotile plates in stationary phase. It is unknown if this growth phase dependent cell shape alteration is a specific feature of Hfx. volcanii, or conserved amongst haloarchaea. Here, we studied the cell shape and motility of two haloarchaea species Haloarcula hispanica and Haloarcula californiae. With a combination of light and electron microscopy, we observed that both strains undergo a growth phase dependent morphological development, albeit in a slightly different fashion as Hfx. volcanii. For both Haloarcula strains, the cell size is changing throughout growth. Cell shape seems to be related with motility, as highly motile cells on semi-solid agar plates are predominantly rod-shaped. We conclude that the growth phase dependent cell morphology alteration might be a common feature amongst haloarchaea, and that cell shape is generally linked with a motile life style. The conservation of this phenomenon underscores the importance of studies of the molecular mechanisms regulating cell shape in archaea.
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Affiliation(s)
- Sabine Schwarzer
- Archaeal Virus-Host Interactions, Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg, Germany;
| | - Marta Rodriguez-Franco
- Cell Biology, Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg, Germany;
| | - Hanna M. Oksanen
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland;
| | - Tessa E. F. Quax
- Archaeal Virus-Host Interactions, Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg, Germany;
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7
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Recalde A, van Wolferen M, Sivabalasarma S, Albers SV, Navarro CA, Jerez CA. The Role of Polyphosphate in Motility, Adhesion, and Biofilm Formation in Sulfolobales. Microorganisms 2021; 9:193. [PMID: 33477546 DOI: 10.3390/microorganisms9010193] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/05/2020] [Accepted: 12/19/2020] [Indexed: 12/25/2022] Open
Abstract
Polyphosphates (polyP) are polymers of orthophosphate residues linked by high-energy phosphoanhydride bonds that are important in all domains of life and function in many different processes, including biofilm development. To study the effect of polyP in archaeal biofilm formation, our previously described Sa. solfataricus polyP (−) strain and a new polyP (−) S. acidocaldarius strain generated in this report were used. These two strains lack the polymer due to the overexpression of their respective exopolyphosphatase gene (ppx). Both strains showed a reduction in biofilm formation, decreased motility on semi-solid plates and a diminished adherence to glass surfaces as seen by DAPI (4′,6-diamidino-2-phenylindole) staining using fluorescence microscopy. Even though arlB (encoding the archaellum subunit) was highly upregulated in S. acidocardarius polyP (−), no archaellated cells were observed. These results suggest that polyP might be involved in the regulation of the expression of archaellum components and their assembly, possibly by affecting energy availability, phosphorylation or other phenomena. This is the first evidence indicating polyP affects biofilm formation and other related processes in archaea.
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8
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Ye X, Vogt MS, van der Does C, Bildl W, Schulte U, Essen LO, Albers SV. Corrigendum: The Phosphatase PP2A Interacts With ArnA and ArnB to Regulate the Oligomeric State and the Stability of the ArnA/B Complex. Front Microbiol 2020; 11:608420. [PMID: 33250888 PMCID: PMC7673380 DOI: 10.3389/fmicb.2020.608420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 10/30/2020] [Indexed: 11/25/2022] Open
Affiliation(s)
- Xing Ye
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | | | - Chris van der Does
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Wolfgang Bildl
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Uwe Schulte
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Biological Signaling Studies (BIOSS), Freiburg, Germany.,Center for Integrative Signaling Studies (CIBSS), Freiburg, Germany
| | - Lars-Oliver Essen
- Department of Chemistry, Philipps University Marburg, Marburg, Germany.,Loewe Center for Synthetic Microbiology, Marburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany.,Center for Biological Signaling Studies (BIOSS), Freiburg, Germany
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9
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Nußbaum P, Ithurbide S, Walsh JC, Patro M, Delpech F, Rodriguez-Franco M, Curmi PMG, Duggin IG, Quax TEF, Albers SV. An Oscillating MinD Protein Determines the Cellular Positioning of the Motility Machinery in Archaea. Curr Biol 2020; 30:4956-4972.e4. [PMID: 33125862 DOI: 10.1016/j.cub.2020.09.073] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/28/2020] [Accepted: 09/23/2020] [Indexed: 01/14/2023]
Abstract
MinD proteins are well studied in rod-shaped bacteria such as E. coli, where they display self-organized pole-to-pole oscillations that are important for correct positioning of the Z-ring at mid-cell for cell division. Archaea also encode proteins belonging to the MinD family, but their functions are unknown. MinD homologous proteins were found to be widespread in Euryarchaeota and form a sister group to the bacterial MinD family, distinct from the ParA and other related ATPase families. We aimed to identify the function of four archaeal MinD proteins in the model archaeon Haloferax volcanii. Deletion of the minD genes did not cause cell division or size defects, and the Z-ring was still correctly positioned. Instead, one of the deletions (ΔminD4) reduced swimming motility and hampered the correct formation of motility machinery at the cell poles. In ΔminD4 cells, there is reduced formation of the motility structure and chemosensory arrays, which are essential for signal transduction. In bacteria, several members of the ParA family can position the motility structure and chemosensory arrays via binding to a landmark protein, and consequently these proteins do not oscillate along the cell axis. However, GFP-MinD4 displayed pole-to-pole oscillation and formed polar patches or foci in H. volcanii. The MinD4 membrane-targeting sequence (MTS), homologous to the bacterial MinD MTS, was essential for the oscillation. Surprisingly, mutant MinD4 proteins failed to form polar patches. Thus, MinD4 from H. volcanii combines traits of different bacterial ParA/MinD proteins.
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Affiliation(s)
- Phillip Nußbaum
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Solenne Ithurbide
- The ithree institute, University of Technology, Sydney, Ultimo, NSW 2007, Australia
| | - James C Walsh
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | - Megha Patro
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Floriane Delpech
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Marta Rodriguez-Franco
- Cell Biology, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
| | - Paul M G Curmi
- School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
| | - Iain G Duggin
- The ithree institute, University of Technology, Sydney, Ultimo, NSW 2007, Australia.
| | - Tessa E F Quax
- Archaeal Virus-Host Interactions, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany.
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany.
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10
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Kinosita Y, Mikami N, Li Z, Braun F, Quax TEF, van der Does C, Ishmukhametov R, Albers SV, Berry RM. Motile ghosts of the halophilic archaeon, Haloferax volcanii. Proc Natl Acad Sci U S A 2020; 117:26766-72. [PMID: 33051299 DOI: 10.1073/pnas.2009814117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Archaea swim using the archaellum (archaeal flagellum), a reversible rotary motor consisting of a torque-generating motor and a helical filament, which acts as a propeller. Unlike the bacterial flagellar motor (BFM), ATP (adenosine-5'-triphosphate) hydrolysis probably drives both motor rotation and filamentous assembly in the archaellum. However, direct evidence is still lacking due to the lack of a versatile model system. Here, we present a membrane-permeabilized ghost system that enables the manipulation of intracellular contents, analogous to the triton model in eukaryotic flagella and gliding Mycoplasma We observed high nucleotide selectivity for ATP driving motor rotation, negative cooperativity in ATP hydrolysis, and the energetic requirement for at least 12 ATP molecules to be hydrolyzed per revolution of the motor. The response regulator CheY increased motor switching from counterclockwise (CCW) to clockwise (CW) rotation. Finally, we constructed the torque-speed curve at various [ATP]s and discuss rotary models in which the archaellum has characteristics of both the BFM and F1-ATPase. Because archaea share similar cell division and chemotaxis machinery with other domains of life, our ghost model will be an important tool for the exploration of the universality, diversity, and evolution of biomolecular machinery.
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11
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Li Z, Rodriguez‐Franco M, Albers S, Quax TEF. The switch complex ArlCDE connects the chemotaxis system and the archaellum. Mol Microbiol 2020; 114:468-479. [PMID: 32416640 PMCID: PMC7534055 DOI: 10.1111/mmi.14527] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 04/09/2020] [Revised: 05/06/2020] [Accepted: 05/08/2020] [Indexed: 12/16/2022]
Abstract
Cells require a sensory system and a motility structure to achieve directed movement. Bacteria and archaea possess rotating filamentous motility structures that work in concert with the sensory chemotaxis system. This allows microorganisms to move along chemical gradients. The central response regulator protein CheY can bind to the motor of the motility structure, the flagellum in bacteria, and the archaellum in archaea. Both motility structures have a fundamentally different protein composition and structural organization. Yet, both systems receive input from the chemotaxis system. So far, it was unknown how the signal is transferred from the archaeal CheY to the archaellum motor to initiate motor switching. We applied a fluorescent microscopy approach in the model euryarchaeon Haloferax volcanii and shed light on the sequence order in which signals are transferred from the chemotaxis system to the archaellum. Our findings indicate that the euryarchaeal-specific ArlCDE are part of the archaellum motor and that they directly receive input from the chemotaxis system via the adaptor protein CheF. Hence, ArlCDE are an important feature of the archaellum of euryarchaea, are essential for signal transduction during chemotaxis and represent the archaeal switch complex.
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Affiliation(s)
- Zhengqun Li
- Molecular Biology of Archaea, Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | | | - Sonja‐Verena Albers
- Molecular Biology of Archaea, Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Tessa E. F. Quax
- Archaeal Virus–Host Interactions, Faculty of BiologyUniversity of FreiburgFreiburgGermany
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12
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Ye X, Vogt MS, van der Does C, Bildl W, Schulte U, Essen LO, Albers SV. The Phosphatase PP2A Interacts With ArnA and ArnB to Regulate the Oligomeric State and the Stability of the ArnA/B Complex. Front Microbiol 2020; 11:1849. [PMID: 32973695 PMCID: PMC7472852 DOI: 10.3389/fmicb.2020.01849] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/15/2020] [Indexed: 12/30/2022] Open
Abstract
In the crenarchaeon Sulfolobus acidocaldarius, the archaellum, a type-IV pilus like motility structure, is synthesized in response to nutrient starvation. Synthesis of components of the archaellum is controlled by the archaellum regulatory network (arn). Protein phosphorylation plays an important role in this regulatory network since the deletion of several genes encoding protein kinases and the phosphatase PP2A affected cell motility. Several proteins in the archaellum regulatory network can be phosphorylated, however, details of how phosphorylation levels of different components affect archaellum synthesis are still unknown. To identify proteins interacting with the S. acidocaldarius phosphatases PTP and PP2A, co-immunoprecipitation assays coupled to mass spectrometry analysis were performed. Thirty minutes after growth in nutrient starvation medium, especially a conserved putative ATP/GTP binding protein (Saci_1281), a universal stress protein (Saci_0887) and the archaellum regulators ArnA and ArnB were identified as highly abundant interaction proteins of PP2A. The interaction between ArnA, ArnB, and PP2A was further studied. Previous studies showed that the Forkhead-associated domain containing ArnA interacts with von Willebrand type A domain containing ArnB, and that both proteins could be phosphorylated by the kinase ArnC in vitro. The ArnA/B heterodimer was reconstituted from the purified proteins. In complex with ArnA, phosphorylation of ArnB by the ArnC kinase was strongly stimulated and resulted in formation of (ArnA/B)2 and higher oligomeric complexes, while association and dephosphorylation by PP2A resulted in dissociation of these ArnA/B complexes.
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Affiliation(s)
- Xing Ye
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | | | - Chris van der Does
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Wolfgang Bildl
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Uwe Schulte
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Biological Signaling Studies(BIOSS), Freiburg, Germany.,Center for Integrative Signaling Studies (CIBSS), Freiburg, Germany
| | - Lars-Oliver Essen
- Department of Chemistry, Philipps University Marburg, Marburg, Germany.,Loewe Center for Synthetic Microbiology, Marburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany.,Center for Biological Signaling Studies(BIOSS), Freiburg, Germany
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13
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Pyatibratov MG, Syutkin AS, Quax TEF, Melnik TN, Papke RT, Gogarten JP, Kireev II, Surin AK, Beznosov SN, Galeva AV, Fedorov OV. Interaction of two strongly divergent archaellins stabilizes the structure of the Halorubrum archaellum. Microbiologyopen 2020; 9:e1047. [PMID: 32352651 PMCID: PMC7349177 DOI: 10.1002/mbo3.1047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 03/23/2020] [Accepted: 03/28/2020] [Indexed: 12/24/2022] Open
Abstract
Halophilic archaea from the genus Halorubrum possess two extraordinarily diverged archaellin genes, flaB1 and flaB2. To clarify roles for each archaellin, we compared two natural Halorubrum lacusprofundi strains: One of them contains both archaellin genes, and the other has the flaB2 gene only. Both strains synthesize functional archaella; however, the strain, where both archaellins are present, is more motile. In addition, we expressed these archaellins in a Haloferax volcanii strain from which the endogenous archaellin genes were deleted. Three Hfx. volcanii strains expressing Hrr. lacusprofundi archaellins produced functional filaments consisting of only one (FlaB1 or FlaB2) or both (FlaB1/FlaB2) archaellins. All three strains were motile, although there were profound differences in the efficiency of motility. Both native and recombinant FlaB1/FlaB2 filaments have greater thermal stability and resistance to low salinity stress than single‐component filaments. Functional supercoiled Hrr. lacusprofundi archaella can be composed of either single archaellin: FlaB2 or FlaB1; however, the two divergent archaellin subunits provide additional stabilization to the archaellum structure and thus adaptation to a wider range of external conditions. Comparative genomic analysis suggests that the described combination of divergent archaellins is not restricted to Hrr. lacusprofundi, but is occurring also in organisms from other haloarchaeal genera.
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Affiliation(s)
- Mikhail G Pyatibratov
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Alexey S Syutkin
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Tessa E F Quax
- Archaeal Virus-Host Interactions, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Tatjana N Melnik
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Igor I Kireev
- A.N. Belozersky Institute of Physico-chemical Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Alexey K Surin
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.,Pushchino Branch, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.,State Research Center for Applied Microbiology & Biotechnology, Obolensk, Moscow Region, Russia
| | - Sergei N Beznosov
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Anna V Galeva
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Oleg V Fedorov
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
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14
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Paithankar KS, Enderle M, Wirthensohn DC, Miller A, Schlesner M, Pfeiffer F, Rittner A, Grininger M, Oesterhelt D. Structure of the archaeal chemotaxis protein CheY in a domain-swapped dimeric conformation. Acta Crystallogr F Struct Biol Commun 2019; 75:576-585. [PMID: 31475924 PMCID: PMC6718144 DOI: 10.1107/s2053230x19010896] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 08/04/2019] [Indexed: 12/15/2022] Open
Abstract
Archaea are motile by the rotation of the archaellum. The archaellum switches between clockwise and counterclockwise rotation, and movement along a chemical gradient is possible by modulation of the switching frequency. This modulation involves the response regulator CheY and the archaellum adaptor protein CheF. In this study, two new crystal forms and protein structures of CheY are reported. In both crystal forms, CheY is arranged in a domain-swapped conformation. CheF, the protein bridging the chemotaxis signal transduction system and the motility apparatus, was recombinantly expressed, purified and subjected to X-ray data collection.
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Affiliation(s)
- Karthik Shivaji Paithankar
- Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - Mathias Enderle
- Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - David C. Wirthensohn
- Department of Membrane Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Arthur Miller
- Department of Membrane Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Matthias Schlesner
- Department of Membrane Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Friedhelm Pfeiffer
- Computational Biology Group, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Alexander Rittner
- Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - Martin Grininger
- Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - Dieter Oesterhelt
- Department of Membrane Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
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15
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Zaretsky M, Darnell CL, Schmid AK, Eichler J. N-Glycosylation Is Important for Halobacterium salinarum Archaellin Expression, Archaellum Assembly and Cell Motility. Front Microbiol 2019; 10:1367. [PMID: 31275283 PMCID: PMC6591318 DOI: 10.3389/fmicb.2019.01367] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 05/31/2019] [Indexed: 12/20/2022] Open
Abstract
Halobacterium salinarum are halophilic archaea that display directional swimming in response to various environmental signals, including light, chemicals and oxygen. In Hbt. salinarum, the building blocks (archaellins) of the archaeal swimming apparatus (the archaellum) are N-glycosylated. However, the physiological importance of archaellin N-glycosylation remains unclear. Here, a tetrasaccharide comprising a hexose and three hexuronic acids decorating the five archaellins was characterized by mass spectrometry. Such analysis failed to detect sulfation of the hexuronic acids, in contrast to earlier reports. To better understand the physiological significance of Hbt. salinarum archaellin N-glycosylation, a strain deleted of aglB, encoding the archaeal oligosaccharyltransferase, was generated. In this ΔaglB strain, archaella were not detected and only low levels of archaellins were released into the medium, in contrast to what occurs with the parent strain. Mass spectrometry analysis of the archaellins in ΔaglB cultures did not detect N-glycosylation. ΔaglB cells also showed a slight growth defect and were impaired for motility. Quantitative real-time PCR analysis revealed dramatically reduced transcript levels of archaellin-encoding genes in the mutant strain, suggesting that N-glycosylation is important for archaellin transcription, with downstream effects on archaellum assembly and function. Control of AglB-dependent post-translational modification of archaellins could thus reflect a previously unrecognized route for regulating Hbt. salinarum motility.
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Affiliation(s)
- Marianna Zaretsky
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheba, Israel
| | | | - Amy K Schmid
- Department of Biology, Duke University, Durham, NC, United States.,Center for Genomics and Computational Biology, Duke University, Durham, NC, United States
| | - Jerry Eichler
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheba, Israel
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16
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Li Z, Kinosita Y, Rodriguez-Franco M, Nußbaum P, Braun F, Delpech F, Quax TEF, Albers SV. Positioning of the Motility Machinery in Halophilic Archaea. mBio 2019; 10:e00377-19. [PMID: 31064826 DOI: 10.1128/mBio.00377-19] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Archaea are ubiquitous single cellular microorganisms that play important ecological roles in nature. The intracellular organization of archaeal cells is among the unresolved mysteries of archaeal biology. With this work, we show that cells of haloarchaea are polarized. The cellular positioning of proteins involved in chemotaxis and motility is spatially and temporally organized in these cells. This suggests the presence of a specific mechanism responsible for the positioning of macromolecular protein complexes in archaea. Bacteria and archaea exhibit tactical behavior and can move up and down chemical gradients. This tactical behavior relies on a motility structure, which is guided by a chemosensory system. Environmental signals are sensed by membrane-inserted chemosensory receptors that are organized in large ordered arrays. While the cellular positioning of the chemotaxis machinery and that of the flagellum have been studied in detail in bacteria, we have little knowledge about the localization of such macromolecular assemblies in archaea. Although the archaeal motility structure, the archaellum, is fundamentally different from the flagellum, archaea have received the chemosensory machinery from bacteria and have connected this system with the archaellum. Here, we applied a combination of time-lapse imaging and fluorescence and electron microscopy using the model euryarchaeon Haloferax volcanii and found that archaella were specifically present at the cell poles of actively dividing rod-shaped cells. The chemosensory arrays also had a polar preference, but in addition, several smaller arrays moved freely in the lateral membranes. In the stationary phase, rod-shaped cells became round and chemosensory arrays were disassembled. The positioning of archaella and that of chemosensory arrays are not interdependent and likely require an independent form of positioning machinery. This work showed that, in the rod-shaped haloarchaeal cells, the positioning of the archaellum and of the chemosensory arrays is regulated in time and in space. These insights into the cellular organization of H. volcanii suggest the presence of an active mechanism responsible for the positioning of macromolecular protein complexes in archaea.
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17
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Daum B, Gold V. Twitch or swim: towards the understanding of prokaryotic motion based on the type IV pilus blueprint. Biol Chem 2019; 399:799-808. [PMID: 29894297 DOI: 10.1515/hsz-2018-0157] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/05/2018] [Indexed: 01/02/2023]
Abstract
Bacteria and archaea are evolutionarily distinct prokaryotes that diverged from a common ancestor billions of years ago. However, both bacteria and archaea assemble long, helical protein filaments on their surface through a machinery that is conserved at its core. In both domains of life, the filaments are required for a diverse array of important cellular processes including cell motility, adhesion, communication and biofilm formation. In this review, we highlight the recent structures of both the type IV pilus machinery and the archaellum determined in situ. We describe the current level of functional understanding and discuss how this relates to the pressures facing bacteria and archaea throughout evolution.
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Affiliation(s)
- Bertram Daum
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.,College of Engineering, Mathematics and Physical Sciences, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Vicki Gold
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.,College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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18
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Abstract
Microorganisms can move towards favorable growth conditions as a response to environmental stimuli. This process requires a motility structure and a system to direct the movement. For swimming motility, archaea employ a rotating filament, the archaellum. This archaea-specific structure is functionally equivalent, but structurally different, from the bacterial flagellum. To control the directionality of movement, some archaea make use of the chemotaxis system, which is used for the same purpose by bacteria. Over the past decades, chemotaxis has been studied in detail in several model bacteria. In contrast, archaeal chemotaxis is much less explored and largely restricted to analyses in halophilic archaea. In this review, we summarize the available information on archaeal taxis. We conclude that archaeal chemotaxis proteins function similarly as their bacterial counterparts. However, because the motility structures are fundamentally different, an archaea-specific docking mechanism is required, for which initial experimental data have only recently been obtained.
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19
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Syutkin AS, van Wolferen M, Surin AK, Albers SV, Pyatibratov MG, Fedorov OV, Quax TEF. Salt-dependent regulation of archaellins in Haloarcula marismortui. Microbiologyopen 2018; 8:e00718. [PMID: 30270530 PMCID: PMC6528647 DOI: 10.1002/mbo3.718] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/31/2018] [Accepted: 08/01/2018] [Indexed: 12/26/2022] Open
Abstract
Microorganisms require a motility structure to move towards optimal growth conditions. The motility structure from archaea, the archaellum, is fundamentally different from its bacterial counterpart, the flagellum, and is assembled in a similar fashion as type IV pili. The archaellum filament consists of thousands of copies of N‐terminally processed archaellin proteins. Several archaea, such as the euryarchaeon Haloarcula marismortui, encode multiple archaellins. Two archaellins of H. marismortui display differential stability under various ionic strengths. This suggests that these proteins behave as ecoparalogs and perform the same function under different environmental conditions. Here, we explored this intriguing system to study the differential regulation of these ecoparalogous archaellins by monitoring their transcription, translation, and assembly into filaments. The salt concentration of the growth medium induced differential expression of the two archaellins. In addition, this analysis indicated that archaellation in H. marismortui is majorly regulated on the level of secretion, by a still unknown mechanism. These findings indicate that in archaea, multiple encoded archaellins are not completely redundant, but in fact can display subtle functional differences, which enable cells to cope with varying environmental conditions.
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Affiliation(s)
- Alexey S Syutkin
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russia
| | - Marleen van Wolferen
- Molecular Biology of Archaea, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Alexey K Surin
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russia
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Oleg V Fedorov
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russia
| | - Tessa E F Quax
- Molecular Biology of Archaea, Faculty of Biology, University of Freiburg, Freiburg, Germany
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20
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Kinosita Y, Nishizaka T. Cross-kymography analysis to simultaneously quantify the function and morphology of the archaellum. Biophys Physicobiol 2018; 15:121-128. [PMID: 29955563 PMCID: PMC6018435 DOI: 10.2142/biophysico.15.0_121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 03/29/2018] [Indexed: 12/13/2022] Open
Abstract
In many microorganisms helical structures are important for motility, e.g., bacterial flagella and kink propagation in Spiroplasma eriocheiris. Motile archaea also form a helical-shaped filament called the ‘archaellum’ that is functionally equivalent to the bacterial flagellum, but structurally resembles type IV pili. The archaellum motor consists of 6–8 proteins called fla accessory genes, and the filament assembly is driven by ATP hydrolysis at catalytic sites in FlaI. Remarkably, previous research using a dark-field microscopy showed that right-handed filaments propelled archaeal cells forwards or backwards by clockwise or counterclockwise rotation, respectively. However, the shape and rotational rate of the archaellum during swimming remained unclear, due to the low signal and lack of temporal resolution. Additionally, the structure and the motor properties of the archaellum and bacterial flagellum have not been precisely determined during swimming because they move freely in three-dimensional space. Recently, we developed an advanced method called “cross-kymography analysis”, which enables us to be a long-term observation and simultaneously quantify the function and morphology of helical structures using a total internal reflection fluorescence microscope. In this review, we introduce the basic idea of this analysis, and summarize the latest information in structural and functional characterization of the archaellum motor.
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Affiliation(s)
- Yoshiaki Kinosita
- Department of Physics, Gakushuin University, Toshima-ku, Tokyo 171-8588, Japan
| | - Takayuki Nishizaka
- Department of Physics, Gakushuin University, Toshima-ku, Tokyo 171-8588, Japan
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21
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Quax TEF, Altegoer F, Rossi F, Li Z, Rodriguez-Franco M, Kraus F, Bange G, Albers SV. Structure and function of the archaeal response regulator CheY. Proc Natl Acad Sci U S A 2018; 115:E1259-68. [PMID: 29358409 DOI: 10.1073/pnas.1716661115] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Motility is a central feature of many microorganisms and provides an efficient strategy to respond to environmental changes. Bacteria and archaea have developed fundamentally different rotary motors enabling their motility, termed flagellum and archaellum, respectively. Bacterial motility along chemical gradients, called chemotaxis, critically relies on the response regulator CheY, which, when phosphorylated, inverses the rotational direction of the flagellum via a switch complex at the base of the motor. The structural difference between archaellum and flagellum and the presence of functional CheY in archaea raises the question of how the CheY protein changed to allow communication with the archaeal motility machinery. Here we show that archaeal CheY shares the overall structure and mechanism of magnesium-dependent phosphorylation with its bacterial counterpart. However, bacterial and archaeal CheY differ in the electrostatic potential of the helix α4. The helix α4 is important in bacteria for interaction with the flagellar switch complex, a structure that is absent in archaea. We demonstrated that phosphorylation-dependent activation, and conserved residues in the archaeal CheY helix α4, are important for interaction with the archaeal-specific adaptor protein CheF. This forms a bridge between the chemotaxis system and the archaeal motility machinery. Conclusively, archaeal CheY proteins conserved the central mechanistic features between bacteria and archaea, but differ in the helix α4 to allow binding to an archaellum-specific interaction partner.
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22
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Ding Y, Berezuk A, Khursigara CM, Jarrell KF. Bypassing the Need for the Transcriptional Activator EarA through a Spontaneous Deletion in the BRE Portion of the fla Operon Promoter in Methanococcus maripaludis. Front Microbiol 2017; 8:1329. [PMID: 28769898 PMCID: PMC5512572 DOI: 10.3389/fmicb.2017.01329] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/30/2017] [Indexed: 11/13/2022] Open
Abstract
In Methanococcus maripaludis, the euryarchaeal archaellum regulator A (EarA) is required for the transcription of the fla operon, which is comprised of a series of genes which encode most of the proteins needed for the formation of the archaeal swimming organelle, the archaellum. In mutants deleted for earA (ΔearA), there is almost undetectable transcription of the fla operon, Fla proteins are not synthesized and the cells are non-archaellated. In this study, we have isolated a spontaneous mutant of a ΔearA mutant in which the restoration of the transcription and translation of the fla operon (using flaB2, the second gene of the operon, as a reporter), archaella formation and swarming motility were all restored even in the absence of EarA. Analysis of the DNA sequence from the fla promoter of this spontaneous mutant revealed a deletion of three adenines within a string of seven adenines in the transcription factor B recognition element (BRE). When the three adenine deletion in the BRE was regenerated in a stock culture of the ΔearA mutant, very similar phenotypes to that of the spontaneous mutant were observed. Deletion of the three adenines in the fla promoter BRE resulted in the mutant BRE having high sequence identity to BREs from promoters that have strong basal transcription level in Mc. maripaludis and Methanocaldococcus jannaschii. These data suggest that EarA may help recruit transcription factor B to a weak BRE in the fla promoter of wild-type cells but is not required for transcription from the fla promoter with a strong BRE, as in the three adenine deletion version in the spontaneous mutant.
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Affiliation(s)
- Yan Ding
- Department of Biomedical and Molecular Sciences, Queen's University, KingstonON, Canada
| | - Alison Berezuk
- Department of Molecular and Cellular Biology, University of Guelph, GuelphON, Canada
| | - Cezar M Khursigara
- Department of Molecular and Cellular Biology, University of Guelph, GuelphON, Canada
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, KingstonON, Canada
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23
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Daum B, Vonck J, Bellack A, Chaudhury P, Reichelt R, Albers SV, Rachel R, Kühlbrandt W. Structure and in situ organisation of the Pyrococcus furiosus archaellum machinery. eLife 2017; 6. [PMID: 28653905 PMCID: PMC5517150 DOI: 10.7554/elife.27470] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/26/2017] [Indexed: 12/25/2022] Open
Abstract
The archaellum is the macromolecular machinery that Archaea use for propulsion or surface adhesion, enabling them to proliferate and invade new territories. The molecular composition of the archaellum and of the motor that drives it appears to be entirely distinct from that of the functionally equivalent bacterial flagellum and flagellar motor. Yet, the structure of the archaellum machinery is scarcely known. Using combined modes of electron cryo-microscopy (cryoEM), we have solved the structure of the Pyrococcus furiosus archaellum filament at 4.2 Å resolution and visualise the architecture and organisation of its motor complex in situ. This allows us to build a structural model combining the archaellum and its motor complex, paving the way to a molecular understanding of archaeal swimming motion.
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Affiliation(s)
- Bertram Daum
- Max Planck Institute of Biophysics, Frankfurt, Germany.,Living Systems Institute, University of Exeter, Exeter, United Kingdom.,College of Physics, Engineering and Physical Science, University of Exeter, Exeter, United Kingdom
| | - Janet Vonck
- Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Annett Bellack
- Institute of Microbiology and Archaea Centre, University of Regensburg, Regensburg, Germany
| | - Paushali Chaudhury
- Institute of Biology II, Molecular Biology of Archaea, University of Freiburg, Freiburg, Germany
| | - Robert Reichelt
- Institute of Microbiology and Archaea Centre, University of Regensburg, Regensburg, Germany
| | - Sonja-Verena Albers
- Institute of Biology II, Molecular Biology of Archaea, University of Freiburg, Freiburg, Germany
| | - Reinhard Rachel
- Institute of Microbiology and Archaea Centre, University of Regensburg, Regensburg, Germany
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24
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Legerme G, Yang E, Esquivel RN, Kiljunen S, Savilahti H, Pohlschroder M. Screening of a Haloferax volcanii Transposon Library Reveals Novel Motility and Adhesion Mutants. Life (Basel) 2016; 6:life6040041. [PMID: 27898036 PMCID: PMC5198076 DOI: 10.3390/life6040041] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/04/2016] [Accepted: 11/07/2016] [Indexed: 12/11/2022] Open
Abstract
Archaea, like bacteria, use type IV pili to facilitate surface adhesion. Moreover, archaeal flagella—structures required for motility—share a common ancestry with type IV pili. While the characterization of archaeal homologs of bacterial type IV pilus biosynthesis components has revealed important aspects of flagellum and pilus biosynthesis and the mechanisms regulating motility and adhesion in archaea, many questions remain. Therefore, we screened a Haloferax volcanii transposon insertion library for motility mutants using motility plates and adhesion mutants, using an adapted air–liquid interface assay. Here, we identify 20 genes, previously unknown to affect motility or adhesion. These genes include potential novel regulatory genes that will help to unravel the mechanisms underpinning these processes. Both screens also identified distinct insertions within the genomic region lying between two chemotaxis genes, suggesting that chemotaxis not only plays a role in archaeal motility, but also in adhesion. Studying these genes, as well as hypothetical genes hvo_2512 and hvo_2876—also critical for both motility and adhesion—will likely elucidate how these two systems interact. Furthermore, this study underscores the usefulness of the transposon library to screen other archaeal cellular processes for specific phenotypic defects.
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Affiliation(s)
- Georgio Legerme
- Department of Biology, University of Pennsylvania, Philadelphia 19104, PA, USA.
| | - Evan Yang
- Department of Biology, University of Pennsylvania, Philadelphia 19104, PA, USA.
| | - Rianne N Esquivel
- Department of Biology, University of Pennsylvania, Philadelphia 19104, PA, USA.
| | - Saija Kiljunen
- Division of Genetics and Physiology, Department of Biology, University of Turku, Turku 20500, Finland.
- Immunobiology Program, Research Programs Unit, University of Helsinki, Fi-00014, Helsinki, Finland.
| | - Harri Savilahti
- Division of Genetics and Physiology, Department of Biology, University of Turku, Turku 20500, Finland.
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25
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Chimileski S, Papke RT. Getting a hold on archaeal type IV pili: an expanding repertoire of cellular appendages implicates complex regulation and diverse functions. Front Microbiol 2015; 6:362. [PMID: 25999922 PMCID: PMC4419858 DOI: 10.3389/fmicb.2015.00362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/10/2015] [Indexed: 12/11/2022] Open
Affiliation(s)
- Scott Chimileski
- Department of Molecular and Cell Biology, University of Connecticut Storrs, CT, USA
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut Storrs, CT, USA
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26
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Abstract
Recent studies on archaeal motility have shown that the archaeal motility structure is unique in several aspects. Although it fulfills the same swimming function as the bacterial flagellum, it is evolutionarily and structurally related to the type IV pilus. This was the basis for the recent proposal to term the archaeal motility structure the "archaellum." This review illustrates the key findings that led to the realization that the archaellum was a novel motility structure and presents the current knowledge about the structural composition, mechanism of assembly and regulation, and the posttranslational modifications of archaella.
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Affiliation(s)
- Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II-Microbiology, University of Freiburg , Freiburg, Germany ; Molecular Biology of Archaea, Max Planck Institute for Terrestrial Microbiology , Marburg, Germany
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University , Kingston, ON, Canada
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Losensky G, Vidakovic L, Klingl A, Pfeifer F, Fröls S. Novel pili-like surface structures of Halobacterium salinarum strain R1 are crucial for surface adhesion. Front Microbiol 2015; 5:755. [PMID: 25628607 PMCID: PMC4292770 DOI: 10.3389/fmicb.2014.00755] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/11/2014] [Indexed: 12/25/2022] Open
Abstract
It was recently shown that haloarchaeal strains of different genera are able to adhere to surfaces and form surface-attached biofilms. However, the surface structures mediating the adhesion were still unknown. We have identified a novel surface structure with Halobacterium salinarum strain R1, crucial for surface adhesion. Electron microscopic studies of surface-attached cells frequently showed pili-like surface structures of two different diameters that were irregularly distributed on the surface. The thinner filaments, 7–8 nm in diameter, represented a so far unobserved novel pili-like structure. Examination of the Hbt. salinarum R1 genome identified two putative gene loci (pil-1 and pil-2) encoding type IV pilus biogenesis complexes besides the archaellum encoding fla gene locus. Both pil-1 and pil-2 were expressed as transcriptional units, and the transcriptional start of pil-1 was identified. In silico analyses revealed that the pil-1 locus is present with other euryarchaeal genomes whereas the pil-2 is restricted to haloarchaea. Comparative real time qRT-PCR studies indicated that the general transcriptional activity was reduced in adherent vs. planktonic cells. In contrast, the transcription of pilB1 and pilB2, encoding putative type IV pilus assembly ATPases, was induced in comparison to the archaella assembly/motor ATPase (flaI) and the ferredoxin gene. Mutant strains were constructed that incurred a flaI deletion or flaI/pilB1 gene deletions. The absence of flaI caused the loss of the archaella while the additional absence of pilB1 led to loss of the novel pili-like surface structures. The ΔflaI/ΔpilB1 double mutants showed a 10-fold reduction in surface adhesion compared to the parental strain. Since surface adhesion was not reduced with the non-archaellated ΔflaI mutants, the pil-1 filaments have a distinct function in the adhesion process.
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Affiliation(s)
- Gerald Losensky
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt Darmstadt, Germany
| | - Lucia Vidakovic
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt Darmstadt, Germany
| | - Andreas Klingl
- Cell Biology and LOEWE Research Centre for Synthetic Microbiology, Philipps-Universität Marburg Marburg, Germany ; Department of Biology I, Biozentrum, University of Munich Planegg-Martinsried, Germany
| | - Felicitas Pfeifer
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt Darmstadt, Germany
| | - Sabrina Fröls
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt Darmstadt, Germany
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Abstract
Prokaryotes have engineered sophisticated surface nanomachines that have allowed them to colonize Earth and thrive even in extreme environments. Filamentous machineries composed of type IV pilins, which are associated with an amazing array of properties ranging from motility to electric conductance, are arguably the most widespread since distinctive proteins dedicated to their biogenesis are found in most known species of prokaryotes. Several decades of investigations, starting with type IV pili and then a variety of related systems both in bacteria and archaea, have outlined common molecular and structural bases for these nanomachines. Using type IV pili as a paradigm, we will highlight in this review common aspects and key biological differences of this group of filamentous structures. Using type IV pili as a paradigm, we review common genetic, structural and mechanistic features (many) as well as differences (few) of the exceptionally widespread and functionally versatile prokaryotic nano-machines composed of type IV pilins.
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Affiliation(s)
- Jamie-Lee Berry
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Vladimir Pelicic
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
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