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Sofer S, Vershinin Z, Mashni L, Zalk R, Shahar A, Eichler J, Grossman-Haham I. Perturbed N-glycosylation of Halobacterium salinarum archaellum filaments leads to filament bundling and compromised cell motility. Nat Commun 2024; 15:5841. [PMID: 38992036 PMCID: PMC11239922 DOI: 10.1038/s41467-024-50277-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 07/03/2024] [Indexed: 07/13/2024] Open
Abstract
The swimming device of archaea-the archaellum-presents asparagine (N)-linked glycans. While N-glycosylation serves numerous roles in archaea, including enabling their survival in extreme environments, how this post-translational modification contributes to cell motility remains under-explored. Here, we report the cryo-EM structure of archaellum filaments from the haloarchaeon Halobacterium salinarum, where archaellins, the building blocks of the archaellum, are N-glycosylated, and the N-glycosylation pathway is well-resolved. We further determined structures of archaellum filaments from two N-glycosylation mutant strains that generate truncated glycans and analyzed their motility. While cells from the parent strain exhibited unidirectional motility, the N-glycosylation mutant strain cells swam in ever-changing directions within a limited area. Although these mutant strain cells presented archaellum filaments that were highly similar in architecture to those of the parent strain, N-linked glycan truncation greatly affected interactions between archaellum filaments, leading to dramatic clustering of both isolated and cell-attached filaments. We propose that the N-linked tetrasaccharides decorating archaellins act as physical spacers that minimize the archaellum filament aggregation that limits cell motility.
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Affiliation(s)
- Shahar Sofer
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Zlata Vershinin
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Leen Mashni
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Ran Zalk
- The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Anat Shahar
- The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Jerry Eichler
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Iris Grossman-Haham
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.
- The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel.
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2
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Liu J, Eastep GN, Cvirkaite-Krupovic V, Rich-New ST, Kreutzberger MAB, Egelman EH, Krupovic M, Wang F. Two distinct archaeal type IV pili structures formed by proteins with identical sequence. Nat Commun 2024; 15:5049. [PMID: 38877064 PMCID: PMC11178852 DOI: 10.1038/s41467-024-45062-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/10/2024] [Indexed: 06/16/2024] Open
Abstract
Type IV pili (T4P) represent one of the most common varieties of surface appendages in archaea. These filaments, assembled from small pilin proteins, can be many microns long and serve diverse functions, including adhesion, biofilm formation, motility, and intercellular communication. Here, we determine atomic structures of two distinct adhesive T4P from Saccharolobus islandicus via cryo-electron microscopy (cryo-EM). Unexpectedly, both pili were assembled from the same pilin polypeptide but under different growth conditions. One filament, denoted mono-pilus, conforms to canonical archaeal T4P structures where all subunits are equivalent, whereas in the other filament, the tri-pilus, the same polypeptide exists in three different conformations. The three conformations in the tri-pilus are very different from the single conformation found in the mono-pilus, and involve different orientations of the outer immunoglobulin-like domains, mediated by a very flexible linker. Remarkably, the outer domains rotate nearly 180° between the mono- and tri-pilus conformations. Both forms of pili require the same ATPase and TadC-like membrane pore for assembly, indicating that the same secretion system can produce structurally very different filaments. Our results show that the structures of archaeal T4P appear to be less constrained and rigid than those of the homologous archaeal flagellar filaments that serve as helical propellers.
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Affiliation(s)
- Junfeng Liu
- Institut Pasteur, Université Paris Cité, Archaeal Virology Unit, Paris, France
| | - Gunnar N Eastep
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Shane T Rich-New
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mark A B Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA.
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, Archaeal Virology Unit, Paris, France.
| | - Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA.
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA.
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3
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Kato S, Tahara YO, Nishimura Y, Uematsu K, Arai T, Nakane D, Ihara A, Nishizaka T, Iwasaki W, Itoh T, Miyata M, Ohkuma M. Cell surface architecture of the cultivated DPANN archaeon Nanobdella aerobiophila. J Bacteriol 2024; 206:e0035123. [PMID: 38289045 PMCID: PMC10882981 DOI: 10.1128/jb.00351-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 12/22/2023] [Indexed: 02/23/2024] Open
Abstract
The DPANN archaeal clade includes obligately ectosymbiotic species. Their cell surfaces potentially play an important role in the symbiotic interaction between the ectosymbionts and their hosts. However, little is known about the mechanism of ectosymbiosis. Here, we show cell surface structures of the cultivated DPANN archaeon Nanobdella aerobiophila strain MJ1T and its host Metallosphaera sedula strain MJ1HA, using a variety of electron microscopy techniques, i.e., negative-staining transmission electron microscopy, quick-freeze deep-etch TEM, and 3D electron tomography. The thickness, unit size, and lattice symmetry of the S-layer of strain MJ1T were different from those of the host archaeon strain MJ1HA. Genomic and transcriptomic analyses highlighted the most highly expressed MJ1T gene for a putative S-layer protein with multiple glycosylation sites and immunoglobulin-like folds, which has no sequence homology to known S-layer proteins. In addition, genes for putative pectin lyase- or lectin-like extracellular proteins, which are potentially involved in symbiotic interaction, were found in the MJ1T genome based on in silico 3D protein structure prediction. Live cell imaging at the optimum growth temperature of 65°C indicated that cell complexes of strains MJ1T and MJ1HA were motile, but sole MJ1T cells were not. Taken together, we propose a model of the symbiotic interaction and cell cycle of Nanobdella aerobiophila.IMPORTANCEDPANN archaea are widely distributed in a variety of natural and artificial environments and may play a considerable role in the microbial ecosystem. All of the cultivated DPANN archaea so far need host organisms for their growth, i.e., obligately ectosymbiotic. However, the mechanism of the ectosymbiosis by DPANN archaea is largely unknown. To this end, we performed a comprehensive analysis of the cultivated DPANN archaeon, Nanobdella aerobiophila, using electron microscopy, live cell imaging, transcriptomics, and genomics, including 3D protein structure prediction. Based on the results, we propose a reasonable model of the symbiotic interaction and cell cycle of Nanobdella aerobiophila, which will enhance our understanding of the enigmatic physiology and ecological significance of DPANN archaea.
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Affiliation(s)
- Shingo Kato
- Japan Collection of Microorganisms (JCM), RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Yuhei O. Tahara
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
| | - Yuki Nishimura
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | | | | | - Daisuke Nakane
- Department of Physics, Gakushuin University, Tokyo, Japan
| | - Ayaka Ihara
- Department of Physics, Gakushuin University, Tokyo, Japan
| | | | - Wataru Iwasaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Takashi Itoh
- Japan Collection of Microorganisms (JCM), RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Makoto Miyata
- Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
| | - Moriya Ohkuma
- Japan Collection of Microorganisms (JCM), RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
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4
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Tawfeeq C, Song J, Khaniya U, Madej T, Wang J, Youkharibache P, Abrol R. Towards a structural and functional analysis of the immunoglobulin-fold proteome. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2024; 138:135-178. [PMID: 38220423 DOI: 10.1016/bs.apcsb.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
The immunoglobulin fold (Ig fold) domain is a super-secondary structural motif consisting of a sandwich with two layers of β-sheets that is present in many proteins with very diverse biological functions covering a wide range of physiological processes. This domain presents a modular architecture built with β strands connected by variable length loops that has a highly conserved structural core of four β-strands and quite variable β-sheet extensions in the two sandwich layers that enable both divergent and convergent evolutionary mechanisms in the known Ig fold proteome. The central role of this Ig fold's structural plasticity in the evolutionary success of antibodies in our immune system is well established. Nature has also utilized this Ig fold in all domains of life in many different physiological contexts that go way beyond the immune system. Here we will present a structural and functional overview of the utilization of the Ig fold in different biological processes and in different cellular contexts to highlight some of the innumerable ways that this structural motif can interact in multidomain proteins to enable their diversity of functions. This includes shareable specific protein structure visualizations behind those functions that serve as starting points for further explorations of the biomolecular interactions spanning the Ig fold proteome. This overview also highlights how this Ig fold is being utilized through natural adaptation, engineering, and even building from scratch for a range of biotechnological applications.
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Affiliation(s)
- Caesar Tawfeeq
- Department of Chemistry and Biochemistry, California State University Northridge, Northridge, United States
| | - James Song
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, United States
| | - Umesh Khaniya
- Cancer Data Science Laboratory, National Cancer Institute, National Institutes of Health, Bethesda, United States
| | - Thomas Madej
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, United States
| | - Jiyao Wang
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, United States
| | - Philippe Youkharibache
- Cancer Data Science Laboratory, National Cancer Institute, National Institutes of Health, Bethesda, United States.
| | - Ravinder Abrol
- Department of Chemistry and Biochemistry, California State University Northridge, Northridge, United States.
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5
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Liu J, Eastep GN, Cvirkaite-Krupovic V, Rich-New ST, Kreutzberger MAB, Egelman EH, Krupovic M, Wang F. Two dramatically distinct archaeal type IV pili structures formed by the same pilin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.07.552285. [PMID: 37609343 PMCID: PMC10441282 DOI: 10.1101/2023.08.07.552285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Type IV pili (T4P) represent one of the most common varieties of surface appendages in archaea. These filaments, assembled from relatively small pilin proteins, can be many microns long and serve diverse functions, including adhesion, biofilm formation, motility, and intercellular communication. Using cryo-electron microscopy (cryo-EM), we determined atomic structures of two dramatically different T4P from Saccharolobus islandicus REY15A. Unexpectedly, both pili were assembled from the same pilin protein but under different growth conditions. One filament, denoted mono-pilus, conforms to canonical archaeal T4P structures where all subunits are equivalent, whereas in the other filament, the tri-pilus, the same protein exists in three different conformations. The three conformations involve different orientations of the outer immunoglobulin (Ig)-like domains, mediated by a very flexible linker, and all three of these conformations are very different from the single conformation found in the mono-pilus. Remarkably, the outer domains rotate nearly 180° between the mono- and tri-pilus conformations, formally similar to what has been shown for outer domains in bacterial flagellar filaments, despite lack of homology between bacterial flagella and archaeal T4P. Interestingly, both forms of pili require the same ATPase and TadC-like membrane pore for assembly, indicating that the same secretion system can produce structurally very different filaments. However, the expression of the ATPase and TadC genes was significantly different under the conditions yielding mono- and tri-pili. While archaeal T4P are homologs of archaeal flagellar filaments, our results show that in contrast to the rigid supercoil that the flagellar filaments must adopt to serve as helical propellers, archaeal T4P are likely to have fewer constraints on their structure and enjoy more internal degrees of freedom.
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6
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Kreutzberger MAB, Cvirkaite-Krupovic V, Liu Y, Baquero DP, Liu J, Sonani RR, Calladine CR, Wang F, Krupovic M, Egelman EH. The evolution of archaeal flagellar filaments. Proc Natl Acad Sci U S A 2023; 120:e2304256120. [PMID: 37399404 PMCID: PMC10334743 DOI: 10.1073/pnas.2304256120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/08/2023] [Indexed: 07/05/2023] Open
Abstract
Flagellar motility has independently arisen three times during evolution: in bacteria, archaea, and eukaryotes. In prokaryotes, the supercoiled flagellar filaments are composed largely of a single protein, bacterial or archaeal flagellin, although these two proteins are not homologous, while in eukaryotes, the flagellum contains hundreds of proteins. Archaeal flagellin and archaeal type IV pilin are homologous, but how archaeal flagellar filaments (AFFs) and archaeal type IV pili (AT4Ps) diverged is not understood, in part, due to the paucity of structures for AFFs and AT4Ps. Despite having similar structures, AFFs supercoil, while AT4Ps do not, and supercoiling is essential for the function of AFFs. We used cryo-electron microscopy to determine the atomic structure of two additional AT4Ps and reanalyzed previous structures. We find that all AFFs have a prominent 10-strand packing, while AT4Ps show a striking structural diversity in their subunit packing. A clear distinction between all AFF and all AT4P structures involves the extension of the N-terminal α-helix with polar residues in the AFFs. Additionally, we characterize a flagellar-like AT4P from Pyrobaculum calidifontis with filament and subunit structure similar to that of AFFs which can be viewed as an evolutionary link, showing how the structural diversity of AT4Ps likely allowed for an AT4P to evolve into a supercoiling AFF.
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Affiliation(s)
- Mark A. B. Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA22903
| | | | - Ying Liu
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, Paris75015, France
| | - Diana P. Baquero
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, Paris75015, France
| | - Junfeng Liu
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, Paris75015, France
| | - Ravi R. Sonani
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA22903
| | - Chris R. Calladine
- Department of Engineering, University of Cambridge, CambridgeCB2 1PZ, United Kingdom
| | - Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA22903
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, Paris75015, France
| | - Edward H. Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA22903
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7
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Zehnle H, Laso-Pérez R, Lipp J, Riedel D, Benito Merino D, Teske A, Wegener G. Candidatus Alkanophaga archaea from Guaymas Basin hydrothermal vent sediment oxidize petroleum alkanes. Nat Microbiol 2023:10.1038/s41564-023-01400-3. [PMID: 37264141 DOI: 10.1038/s41564-023-01400-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 04/28/2023] [Indexed: 06/03/2023]
Abstract
Methanogenic and methanotrophic archaea produce and consume the greenhouse gas methane, respectively, using the reversible enzyme methyl-coenzyme M reductase (Mcr). Recently, Mcr variants that can activate multicarbon alkanes have been recovered from archaeal enrichment cultures. These enzymes, called alkyl-coenzyme M reductase (Acrs), are widespread in the environment but remain poorly understood. Here we produced anoxic cultures degrading mid-chain petroleum n-alkanes between pentane (C5) and tetradecane (C14) at 70 °C using oil-rich Guaymas Basin sediments. In these cultures, archaea of the genus Candidatus Alkanophaga activate the alkanes with Acrs and completely oxidize the alkyl groups to CO2. Ca. Alkanophaga form a deep-branching sister clade to the methanotrophs ANME-1 and are closely related to the short-chain alkane oxidizers Ca. Syntrophoarchaeum. Incapable of sulfate reduction, Ca. Alkanophaga shuttle electrons released from alkane oxidation to the sulfate-reducing Ca. Thermodesulfobacterium syntrophicum. These syntrophic consortia are potential key players in petroleum degradation in heated oil reservoirs.
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Affiliation(s)
- Hanna Zehnle
- Max Planck Institute for Marine Microbiology, Bremen, Germany.
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany.
- Faculty of Geosciences, University of Bremen, Bremen, Germany.
| | - Rafael Laso-Pérez
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
- Systems Biology Department, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
- Biogeochemistry and Microbial Ecology Department, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
| | - Julius Lipp
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Dietmar Riedel
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - David Benito Merino
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- Faculty of Geosciences, University of Bremen, Bremen, Germany
| | - Andreas Teske
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Gunter Wegener
- Max Planck Institute for Marine Microbiology, Bremen, Germany.
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany.
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8
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Makarova KS, Wolf YI, Karamycheva S, Koonin EV. A Unique Gene Module in Thermococcales Archaea Centered on a Hypervariable Protein Containing Immunoglobulin Domains. Front Microbiol 2021; 12:721392. [PMID: 34489912 PMCID: PMC8416519 DOI: 10.3389/fmicb.2021.721392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/22/2021] [Indexed: 11/17/2022] Open
Abstract
Molecular mechanisms involved in biological conflicts and self vs nonself recognition in archaea remain poorly characterized. We apply phylogenomic analysis to identify a hypervariable gene module that is widespread among Thermococcales. These loci consist of an upstream gene coding for a large protein containing several immunoglobulin (Ig) domains and unique combinations of downstream genes, some of which also contain Ig domains. In the large Ig domain containing protein, the C-terminal Ig domain sequence is hypervariable, apparently, as a result of recombination between genes from different Thermococcales. To reflect the hypervariability, we denote this gene module VARTIG (VARiable Thermococcales IG). The overall organization of the VARTIG modules is similar to the organization of Polymorphic Toxin Systems (PTS). Archaeal genomes outside Thermococcales encode a variety of Ig domain proteins, but no counterparts to VARTIG and no Ig domains with comparable levels of variability. The specific functions of VARTIG remain unknown but the identified features of this system imply three testable hypotheses: (i) involvement in inter-microbial conflicts analogous to PTS, (ii) role in innate immunity analogous to the vertebrate complement system, and (iii) function in self vs nonself discrimination analogous to the vertebrate Major Histocompatibility Complex. The latter two hypotheses seem to be of particular interest given the apparent analogy to the vertebrate immunity.
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Affiliation(s)
- Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, United States
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, United States
| | - Svetlana Karamycheva
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, United States
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, United States
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9
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Functional compartmentalization and metabolic separation in a prokaryotic cell. Proc Natl Acad Sci U S A 2021; 118:2022114118. [PMID: 34161262 DOI: 10.1073/pnas.2022114118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The prokaryotic cell is traditionally seen as a "bag of enzymes," yet its organization is much more complex than in this simplified view. By now, various microcompartments encapsulating metabolic enzymes or pathways are known for Bacteria These microcompartments are usually small, encapsulating and concentrating only a few enzymes, thus protecting the cell from toxic intermediates or preventing unwanted side reactions. The hyperthermophilic, strictly anaerobic Crenarchaeon Ignicoccus hospitalis is an extraordinary organism possessing two membranes, an inner and an energized outer membrane. The outer membrane (termed here outer cytoplasmic membrane) harbors enzymes involved in proton gradient generation and ATP synthesis. These two membranes are separated by an intermembrane compartment, whose function is unknown. Major information processes like DNA replication, RNA synthesis, and protein biosynthesis are located inside the "cytoplasm" or central cytoplasmic compartment. Here, we show by immunogold labeling of ultrathin sections that enzymes involved in autotrophic CO2 assimilation are located in the intermembrane compartment that we name (now) a peripheric cytoplasmic compartment. This separation may protect DNA and RNA from reactive aldehydes arising in the I. hospitalis carbon metabolism. This compartmentalization of metabolic pathways and information processes is unprecedented in the prokaryotic world, representing a unique example of spatiofunctional compartmentalization in the second domain of life.
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10
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Structural interactions define assembly adapter function of a type II secretion system pseudopilin. Structure 2021; 29:1116-1127.e8. [PMID: 34139172 DOI: 10.1016/j.str.2021.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/15/2021] [Accepted: 05/28/2021] [Indexed: 01/13/2023]
Abstract
The type IV filament superfamily comprises widespread membrane-associated polymers in prokaryotes. The type II secretion system (T2SS), a virulence pathway in many pathogens, belongs to this superfamily. A knowledge gap in understanding of the T2SS is the molecular role of a small "pseudopilin" protein. Using multiple biophysical techniques, we have deciphered how this missing component of the Xcp T2SS architecture is structurally integrated, and thereby unlocked its function. We demonstrate that low-abundance XcpH is the adapter that bridges a trimeric initiating tip complex, XcpIJK, with a periplasmic filament of XcpG subunits. Each pseudopilin protein caps an XcpG protofilament in an overall pseudopilus compatible with dimensions of the periplasm and the outer membrane-spanning secretin through which substrates pass. Unexpectedly, to fulfill its adapter function, the XcpH N-terminal helix must be unwound, a property shared with XcpG subunits. We provide an experimentally validated three-dimensional structural model of a complete type IV filament.
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11
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Elshiaty M, Schindler H, Christopoulos P. Principles and Current Clinical Landscape of Multispecific Antibodies against Cancer. Int J Mol Sci 2021; 22:5632. [PMID: 34073188 PMCID: PMC8198225 DOI: 10.3390/ijms22115632] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 02/07/2023] Open
Abstract
Building upon the resounding therapeutic success of monoclonal antibodies, and supported by accelerating progress in engineering methods, the field of multispecific therapeutic antibodies is growing rapidly. Over 140 different molecules are currently in clinical testing, with excellent results in recent phase 1-3 clinical trials for several of them. Multivalent bispecific IgG-modified formats predominate today, with a clear tendency for more target antigens and further increased valency in newer constructs. The strategies to augment anticancer efficacy are currently equally divided between disruption of multiple surface antigens, and additional redirection of cytotoxic T or NK lymphocytes against the tumor. Both effects complement other modern modalities, such as tyrosine kinase inhibitors and adoptive cell therapies, with which multispecifics are increasingly applied in combination or merged, for example, in the form of antibody producing CAR-T cells and oncolytics. While mainly focused on B-cell malignancies early on, the contemporary multispecific antibody sector accommodates twice as many trials against solid compared to hematologic cancers. An exciting emerging prospect is the targeting of intracellular neoantigens using T-cell receptor (TCR) fusion proteins or TCR-mimic antibody fragments. Considering the fact that introduction of PD-(L)1 inhibitors only a few years ago has already facilitated 5-year survival rates of 30-50% for per se highly lethal neoplasms, such as metastatic melanoma and non-small-cell lung carcinoma, the upcoming enforcement of current treatments with "next-generation" immunotherapeutics, offers a justified hope for the cure of some advanced cancers in the near future.
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Affiliation(s)
- Mariam Elshiaty
- Thoraxklinik and National Center for Tumor Diseases (NCT) at Heidelberg University Hospital, 69126 Heidelberg, Germany; (M.E.); (H.S.)
- Translational Lung Cancer Center Heidelberg, Member of the German Center for Lung Research (DZL), 69126 Heidelberg, Germany
| | - Hannah Schindler
- Thoraxklinik and National Center for Tumor Diseases (NCT) at Heidelberg University Hospital, 69126 Heidelberg, Germany; (M.E.); (H.S.)
- Translational Lung Cancer Center Heidelberg, Member of the German Center for Lung Research (DZL), 69126 Heidelberg, Germany
| | - Petros Christopoulos
- Thoraxklinik and National Center for Tumor Diseases (NCT) at Heidelberg University Hospital, 69126 Heidelberg, Germany; (M.E.); (H.S.)
- Translational Lung Cancer Center Heidelberg, Member of the German Center for Lung Research (DZL), 69126 Heidelberg, Germany
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12
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Oreste U, Ametrano A, Coscia MR. On Origin and Evolution of the Antibody Molecule. BIOLOGY 2021; 10:biology10020140. [PMID: 33578914 PMCID: PMC7916673 DOI: 10.3390/biology10020140] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 12/29/2022]
Abstract
Simple Summary Like many other molecules playing vital functions in animals, the antibody molecule possesses a complex structure with distinctive features. The structure of the basic unit, i.e., the immunoglobulin domain of very ancient origin is substantially simple. However, high complexity resides in the types and numbers of the domains composing the whole molecule. The emergence of the antibody molecule during evolution overturned the effectiveness of the organisms’ defense system. The particular organization of the coding genes, the mechanisms generating antibody diversity, and the plasticity of the overall protein structure, attest to an extraordinary successful evolutionary history. Here, we attempt to trace, across the evolutionary scale, the very early origins of the most significant features characterizing the structure of the antibody molecule and of the molecular mechanisms underlying its major role in recognizing an almost unlimited number of pathogens. Abstract The vertebrate immune system provides a powerful defense because of the ability to potentially recognize an unlimited number of pathogens. The antibody molecule, also termed immunoglobulin (Ig) is one of the major mediators of the immune response. It is built up from two types of Ig domains: the variable domain, which provides the capability to recognize and bind a potentially infinite range of foreign substances, and the constant domains, which exert the effector functions. In the last 20 years, advances in our understanding of the molecular mechanisms and structural features of antibody in mammals and in a variety of other organisms have uncovered the underlying principles and complexity of this fundamental molecule. One notable evolutionary topic is the origin and evolution of antibody. Many aspects have been clearly stated, but some others remain limited or obscure. By considering a wide range of prokaryotic and eukaryotic organisms through a literature survey about the topic, we have provided an integrated view of the emergence of antibodies in evolution and underlined the very ancient origins.
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Affiliation(s)
- Umberto Oreste
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
| | - Alessia Ametrano
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania Luigi Vanvitelli, 81100 Caserta, Italy
| | - Maria Rosaria Coscia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
- Correspondence: ; Tel.: +39-081-6132556
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13
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The structures of two archaeal type IV pili illuminate evolutionary relationships. Nat Commun 2020; 11:3424. [PMID: 32647180 PMCID: PMC7347861 DOI: 10.1038/s41467-020-17268-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/22/2020] [Indexed: 12/14/2022] Open
Abstract
We have determined the cryo-electron microscopic (cryo-EM) structures of two archaeal type IV pili (T4P), from Pyrobaculum arsenaticum and Saccharolobus solfataricus, at 3.8 Å and 3.4 Å resolution, respectively. This triples the number of high resolution archaeal T4P structures, and allows us to pinpoint the evolutionary divergence of bacterial T4P, archaeal T4P and archaeal flagellar filaments. We suggest that extensive glycosylation previously observed in T4P of Sulfolobus islandicus is a response to an acidic environment, as at even higher temperatures in a neutral environment much less glycosylation is present for Pyrobaculum than for Sulfolobus and Saccharolobus pili. Consequently, the Pyrobaculum filaments do not display the remarkable stability of the Sulfolobus filaments in vitro. We identify the Saccharolobus and Pyrobaculum T4P as host receptors recognized by rudivirus SSRV1 and tristromavirus PFV2, respectively. Our results illuminate the evolutionary relationships among bacterial and archaeal T4P filaments and provide insights into archaeal virus-host interactions. Archaeal type IV pili (T4P) mediate adhesion to surfaces and are receptors for hyperthermophilic archaeal viruses. Here, the authors present the cryo-EM structures of two archaeal T4P from Pyrobaculum arsenaticum and Saccharolobus solfataricus and discuss evolutionary relationships between bacterial T4P, archaeal T4P and archaeal flagellar filaments.
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14
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Thompson MC, Yeates TO, Rodriguez JA. Advances in methods for atomic resolution macromolecular structure determination. F1000Res 2020; 9:F1000 Faculty Rev-667. [PMID: 32676184 PMCID: PMC7333361 DOI: 10.12688/f1000research.25097.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/25/2020] [Indexed: 12/13/2022] Open
Abstract
Recent technical advances have dramatically increased the power and scope of structural biology. New developments in high-resolution cryo-electron microscopy, serial X-ray crystallography, and electron diffraction have been especially transformative. Here we highlight some of the latest advances and current challenges at the frontiers of atomic resolution methods for elucidating the structures and dynamical properties of macromolecules and their complexes.
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Affiliation(s)
- Michael C. Thompson
- Department of Chemistry and Chemical Biology, University of California, Merced, CA, USA
| | - Todd O. Yeates
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA, USA
| | - Jose A. Rodriguez
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA, USA
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15
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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] [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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16
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Architecture and modular assembly of Sulfolobus S-layers revealed by electron cryotomography. Proc Natl Acad Sci U S A 2019; 116:25278-25286. [PMID: 31767763 PMCID: PMC6911244 DOI: 10.1073/pnas.1911262116] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Many bacteria and most archaea are enveloped in S-layers, protective lattices of proteins that are among the most abundant on earth. S-layers define both the cell’s shape and periplasmic space, and play essential roles in cell division, adhesion, biofilm formation, protection against harsh environments and phages, and comprise important virulence factors in pathogenic bacteria. Despite their importance, structural information about archaeal S-layers is sparse. Here, we describe in situ structural data on archaeal S-layers by cutting-edge electron cryotomography. Our results shed light on the function and evolution of archaeal cell walls and thus our understanding of microbial life. They will also inform approaches in nanobiotechnology aiming to engineer S-layers for a vast array of applications. Surface protein layers (S-layers) often form the only structural component of the archaeal cell wall and are therefore important for cell survival. S-layers have a plethora of cellular functions including maintenance of cell shape, osmotic, and mechanical stability, the formation of a semipermeable protective barrier around the cell, and cell–cell interaction, as well as surface adhesion. Despite the central importance of S-layers for archaeal life, their 3-dimensional (3D) architecture is still poorly understood. Here we present detailed 3D electron cryomicroscopy maps of archaeal S-layers from 3 different Sulfolobus strains. We were able to pinpoint the positions and determine the structure of the 2 subunits SlaA and SlaB. We also present a model describing the assembly of the mature S-layer.
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17
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Chen H, Xu J, Tan W, Fang L. Lead binding to wild metal-resistant bacteria analyzed by ITC and XAFS spectroscopy. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 250:118-126. [PMID: 30991280 DOI: 10.1016/j.envpol.2019.03.123] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/23/2019] [Accepted: 03/29/2019] [Indexed: 05/26/2023]
Abstract
Metal-resistant bacteria can survive exposure to high metal concentrations without any negative impact on their growth. Biosorption is considered to be one of the more effective detoxification mechanisms acting in most bacteria. However, molecular-scale characterization of metal biosorption by wild metal-resistant bacteria has been limited. In this study, the Pb(II) biosorption behavior of Serratia Se1998 isolated from Pb-contaminated soil was investigated through macroscopic and microscopic techniques. A four discrete site non-electrostatic model fit the potentiometric titration data best, suggesting a distribution of phosphodiester, carboxyl, phosphoryl, and amino or hydroxyl groups on the cell surface. The presence of these functional groups was verified by the attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, which also indicated that carboxyl and phosphoryl sites participated in Pb(II) binding simultaneously. The negative enthalpy (-9.11 kJ mol-1) and large positive entropy (81.52 J mol-1 K-1) of Pb(II) binding with the bacteria suggested the formation of inner-sphere complexes by an exothermic process. X-ray absorption fine structure (XAFS) analysis further indicated monodentate inner-sphere binding of Pb(II) through formation of C-O-Pb and P-O-Pb bonds. We inferred that C-O-Pb bonds formed on the flagellar surfaces, establishing a self-protective barrier against exterior metal stressors. This study has important implications for an improved understanding of metal-resistance mechanisms in wild bacteria and provides guidance for the construction of genetically engineered bacteria for remediation purposes.
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Affiliation(s)
- Hansong Chen
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, 712100, China; University of Chinese Academy of Sciences, Beijing, 100049, China; College of Xingzhi, Zhejiang Normal University, Jinhua, 321000, China
| | - Jinling Xu
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, 712100, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenfeng Tan
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, 712100, China
| | - Linchuan Fang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, 712100, China; CAS Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xian, 710061, China.
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18
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Wang F, Cvirkaite-Krupovic V, Kreutzberger MAB, Su Z, de Oliveira GAP, Osinski T, Sherman N, DiMaio F, Wall JS, Prangishvili D, Krupovic M, Egelman EH. An extensively glycosylated archaeal pilus survives extreme conditions. Nat Microbiol 2019; 4:1401-1410. [PMID: 31110358 PMCID: PMC6656605 DOI: 10.1038/s41564-019-0458-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 04/15/2019] [Indexed: 11/09/2022]
Abstract
Pili on the surface of Sulfolobus islandicus are used for many functions, and serve as receptors for certain archaeal viruses. The cells grow optimally at pH 3 and ~80 °C, exposing these extracellular appendages to a very harsh environment. The pili, when removed from cells, resist digestion by trypsin or pepsin, and survive boiling in sodium dodecyl sulfate or 5 M guanidine hydrochloride. We used electron cryo-microscopy to determine the structure of these filaments at 4.1 Å resolution. An atomic model was built by combining the electron density map with bioinformatics without previous knowledge of the pilin sequence-an approach that should prove useful for assemblies where all of the components are not known. The atomic structure of the pilus was unusual, with almost one-third of the residues being either threonine or serine, and with many hydrophobic surface residues. While the map showed extra density consistent with glycosylation for only three residues, mass measurements suggested extensive glycosylation. We propose that this extensive glycosylation renders these filaments soluble and provides the remarkable structural stability. We also show that the overall fold of the archaeal pilin is remarkably similar to that of archaeal flagellin, establishing common evolutionary origins.
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Affiliation(s)
- Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | | | - Mark A B Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Zhangli Su
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | | | - Tomasz Osinski
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Nicholas Sherman
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | | | - David Prangishvili
- Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, Institut Pasteur, Paris, France
| | - Mart Krupovic
- Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, Institut Pasteur, Paris, France.
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA.
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19
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Kobus S, Perez-Garcia P, Hoeppner A, Holzscheck N, Kovacic F, Streit WR, Jaeger KE, Chow J, Smits SHJ. Igni18, a novel metallo-hydrolase from the hyperthermophilic archaeon Ignicoccus hospitalis KIN4/I: cloning, expression, purification and X-ray analysis. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2019; 75:307-311. [PMID: 30950832 DOI: 10.1107/s2053230x19002851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 02/25/2019] [Indexed: 11/10/2022]
Abstract
The hyperthermophilic crenarchaeon Ignicoccus hospitalis KIN4/I possesses at least 35 putative genes encoding enzymes that belong to the α/β-hydrolase superfamily. One of those genes, the metallo-hydrolase-encoding igni18, was cloned and heterologously expressed in Pichia pastoris. The enzyme produced was purified in its catalytically active form. The recombinant enzyme was successfully crystallized and the crystal diffracted to a resolution of 2.3 Å. The crystal belonged to space group R32, with unit-cell parameters a = b = 67.42, c = 253.77 Å, α = β = 90.0, γ = 120.0°. It is suggested that it contains one monomer of Igni18 within the asymmetric unit.
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Affiliation(s)
- Stefanie Kobus
- Center for Structural Studies (CSS), Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Pablo Perez-Garcia
- Department of Microbiology and Biotechnology, University of Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany
| | - Astrid Hoeppner
- Center for Structural Studies (CSS), Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Nicholas Holzscheck
- Department of Microbiology and Biotechnology, University of Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany
| | - Filip Kovacic
- Institute of Molecular Enzyme Technology (IMET), Heinrich Heine University Düsseldorf, 52426 Jülich, Germany
| | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, University of Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany
| | - Karl Erich Jaeger
- Institute of Molecular Enzyme Technology (IMET), Heinrich Heine University Düsseldorf, 52426 Jülich, Germany
| | - Jennifer Chow
- Department of Microbiology and Biotechnology, University of Hamburg, Ohnhorststrasse 18, 22609 Hamburg, Germany
| | - Sander H J Smits
- Center for Structural Studies (CSS), Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
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20
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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] [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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21
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Meshcheryakov VA, Shibata S, Schreiber MT, Villar-Briones A, Jarrell KF, Aizawa SI, Wolf M. High-resolution archaellum structure reveals a conserved metal-binding site. EMBO Rep 2019; 20:embr.201846340. [PMID: 30898768 PMCID: PMC6500986 DOI: 10.15252/embr.201846340] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 02/16/2019] [Accepted: 02/27/2019] [Indexed: 01/09/2023] Open
Abstract
Many archaea swim by means of archaella. While the archaellum is similar in function to its bacterial counterpart, its structure, composition, and evolution are fundamentally different. Archaella are related to archaeal and bacterial type IV pili. Despite recent advances, our understanding of molecular processes governing archaellum assembly and stability is still incomplete. Here, we determine the structures of Methanococcus archaella by X‐ray crystallography and cryo‐EM. The crystal structure of Methanocaldococcus jannaschii FlaB1 is the first and only crystal structure of any archaellin to date at a resolution of 1.5 Å, which is put into biological context by a cryo‐EM reconstruction from Methanococcus maripaludis archaella at 4 Å resolution created with helical single‐particle analysis. Our results indicate that the archaellum is predominantly composed of FlaB1. We identify N‐linked glycosylation by cryo‐EM and mass spectrometry. The crystal structure reveals a highly conserved metal‐binding site, which is validated by mass spectrometry and electron energy‐loss spectroscopy. We show in vitro that the metal‐binding site, which appears to be a widespread property of archaellin, is required for filament integrity.
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Affiliation(s)
- Vladimir A Meshcheryakov
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Kunigami, Okinawa, Japan
| | - Satoshi Shibata
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Kunigami, Okinawa, Japan
| | - Makoto Tokoro Schreiber
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Kunigami, Okinawa, Japan
| | - Alejandro Villar-Briones
- Instrumental Analysis Section, Okinawa Institute of Science and Technology Graduate University, Onna, Kunigami, Okinawa, Japan
| | - Kenneth F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Shin-Ichi Aizawa
- Department of Life Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima, Japan
| | - Matthias Wolf
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Kunigami, Okinawa, Japan
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22
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Abstract
Bacterial uptake of DNA through type IV filaments is an essential component of natural competence in numerous gram-positive and gram-negative species. Recent advances in the field have broadened our understanding of the structures used to take up extracellular DNA. Here, we review seminal experiments in the literature describing DNA binding by type IV pili, competence pili and the flp pili of Micrococcus luteus; collectively referred to here as type IV filaments. We compare the current state of the field on mechanisms of DNA uptake for these three appendage systems and describe the current mechanistic understanding of both DNA-binding and DNA-uptake by these versatile molecular machines.
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Affiliation(s)
- Kurt H Piepenbrink
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, United States.,Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, United States.,Nebraska Food for Health Center, University of Nebraska-Lincoln, Lincoln, NE, United States.,Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE, United States
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23
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Chen B, Fang L, Yan X, Zhang A, Chen P, Luan T, Hu L, Jiang G. A unique Pb-binding flagellin as an effective remediation tool for Pb contamination in aquatic environment. JOURNAL OF HAZARDOUS MATERIALS 2019; 363:34-40. [PMID: 30300776 DOI: 10.1016/j.jhazmat.2018.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/10/2018] [Accepted: 10/01/2018] [Indexed: 06/08/2023]
Abstract
Metal contaminants present persistent and deleterious threats to environmental ecosystems and human health. Microorganisms can rapidly develop protective mechanisms against metal toxicity, such as metallothionein production. The identification of biological factors related to these protective mechanisms is essential for effective metal remediation. This study presents a robust pathway to rapidly locate and characterize a Pb-binding flagellin in Serratia Se1998, which can bind Pb at a 16:1 Pb: protein ratio. A column gel electrophoresis system hyphenated with inductively coupled plasma mass spectrometry (ICP MS) was constructed to efficiently separate and identify Pb-binding proteins from the whole bacterial proteome. PCR and transgenic assays were used to elucidate the exact sequences and biological function of Pb-binding proteins and heterogeneous expression of Pb-binding flagellin in E. coli could significantly enhance Pb removal from aqueous solution by approximately 45%. This method provides a benchmark procedure to rapidly identify biological factors responsible for metal biosorption. Identification of this unique Pb-binding flagellin highlights that microorganisms can survive high metal stresses due to various complex biological pathways for metal detoxification and remediation.
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Affiliation(s)
- Baowei Chen
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Linchuan Fang
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, 712100, PR China
| | - Xueting Yan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, PR China
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, PR China
| | - Ping Chen
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China
| | - Tiangang Luan
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, PR China; School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Ligang Hu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, PR China.
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, PR China
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24
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Chaudhury P, van der Does C, Albers SV. Characterization of the ATPase FlaI of the motor complex of the Pyrococcus furiosus archaellum and its interactions between the ATP-binding protein FlaH. PeerJ 2018; 6:e4984. [PMID: 29938130 PMCID: PMC6011876 DOI: 10.7717/peerj.4984] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/25/2018] [Indexed: 01/09/2023] Open
Abstract
The archaellum, the rotating motility structure of archaea, is best studied in the crenarchaeon Sulfolobus acidocaldarius. To better understand how assembly and rotation of this structure is driven, two ATP-binding proteins, FlaI and FlaH of the motor complex of the archaellum of the euryarchaeon Pyrococcus furiosus, were overexpressed, purified and studied. Contrary to the FlaI ATPase of S. acidocaldarius, which only forms a hexamer after binding of nucleotides, FlaI of P. furiosus formed a hexamer in a nucleotide independent manner. In this hexamer only 2 of the ATP binding sites were available for binding of the fluorescent ATP-analog MANT-ATP, suggesting a twofold symmetry in the hexamer. P. furiosus FlaI showed a 250-fold higher ATPase activity than S. acidocaldarius FlaI. Interaction studies between the isolated N- and C-terminal domains of FlaI showed interactions between the N- and C-terminal domains and strong interactions between the N-terminal domains not previously observed for ATPases involved in archaellum assembly. These interactions played a role in oligomerization and activity, suggesting a conformational state of the hexamer not observed before. Further interaction studies show that the C-terminal domain of PfFlaI interacts with the nucleotide binding protein FlaH. This interaction stimulates the ATPase activity of FlaI optimally at a 1:1 stoichiometry, suggesting that hexameric PfFlaI interacts with hexameric PfFlaH. These data help to further understand the complex interactions that are required to energize the archaellar motor.
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Affiliation(s)
- Paushali Chaudhury
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Freiburg, Germany
| | - Chris van der Does
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Freiburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Freiburg, Germany
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25
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Wirth R, Luckner M, Wanner G. Validation of a Hypothesis: Colonization of Black Smokers by Hyperthermophilic Microorganisms. Front Microbiol 2018; 9:524. [PMID: 29619021 PMCID: PMC5871681 DOI: 10.3389/fmicb.2018.00524] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/08/2018] [Indexed: 11/22/2022] Open
Abstract
Newly erupted black smokers (hydrothermal vent chimneys) are sterile during their formation, but house hyperthermophilic microorganisms in substantial amounts in later stages. No direct experimental data exist by which mechanisms hyperthermophiles colonize newly erupted black smokers, but a scenario was proposed recently how this might happen. Here we combine high temperature light microscopy with electron microscopy to show that two hyperthermophilic Archaea, namely Pyrococcus furiosus and Methanocaldococcus villosus are able to adhere onto authentic black smoker material (BSM). We especially are able to directly observe the adhesion process via video recordings taken at high temperatures. These data validate the hypothesis that hyperthermophiles are transferred by serendipitous water currents to the outside of newly formed black smokers and react within seconds to the there prevailing high temperatures by very fast movements. They scan the surface of the hydrothermal chimneys via a much slower zigzag seek-movement and adhere via their flagella at a suitable place, building up biofilms.
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Affiliation(s)
- Reinhard Wirth
- Faculty of Biology, Archaea Centre, University of Regensburg, Regensburg, Germany
| | - Manja Luckner
- Department of Biology I, Ludwig-Maximilians-University, Munich, Germany
| | - Gerhard Wanner
- Department of Biology I, Ludwig-Maximilians-University, Munich, Germany
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26
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Wang F, Coureuil M, Osinski T, Orlova A, Altindal T, Gesbert G, Nassif X, Egelman EH, Craig L. Cryoelectron Microscopy Reconstructions of the Pseudomonas aeruginosa and Neisseria gonorrhoeae Type IV Pili at Sub-nanometer Resolution. Structure 2018; 25:1423-1435.e4. [PMID: 28877506 DOI: 10.1016/j.str.2017.07.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 06/03/2017] [Accepted: 07/25/2017] [Indexed: 01/17/2023]
Abstract
We report here cryoelectron microscopy reconstructions of type IV pili (T4P) from two important human pathogens, Pseudomonas aeruginosa and Neisseria gonorrhoeae, at ∼ 8 and 5 Å resolution, respectively. The two structures reveal distinct arrangements of the pilin globular domains on the pilus surfaces, which impart different helical parameters, but similar packing of the conserved N-terminal α helices, α1, in the filament core. In contrast to the continuous α helix seen in the X-ray crystal structures of the P. aeruginosa and N. gonorrhoeae pilin subunits, α1 in the pilus filaments has a melted segment located between conserved helix-breaking residues Gly14 and Pro22, as seen for the Neisseria meningitidis T4P. Using mutagenesis we show that Pro22 is critical for pilus assembly, as are Thr2 and Glu5, which are positioned to interact in the hydrophobic filament core. These structures provide a framework for understanding T4P assembly, function, and biophysical properties.
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Affiliation(s)
- Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Mathieu Coureuil
- Institut Necker-Enfants Malades, INSERM U1151, 14 Rue Maria Helena Vieira Da Silva, CS 61431, 75014 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, 15 Rue de l'École de Médecine, 75006 Paris, France
| | - Tomasz Osinski
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Albina Orlova
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Tuba Altindal
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Gaël Gesbert
- Institut Necker-Enfants Malades, INSERM U1151, 14 Rue Maria Helena Vieira Da Silva, CS 61431, 75014 Paris, France
| | - Xavier Nassif
- Institut Necker-Enfants Malades, INSERM U1151, 14 Rue Maria Helena Vieira Da Silva, CS 61431, 75014 Paris, France
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
| | - Lisa Craig
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
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27
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Direct imaging and computational cryo-electron microscopy of ribbons and nanotubes. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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28
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Albers SV, Jarrell KF. The Archaellum: An Update on the Unique Archaeal Motility Structure. Trends Microbiol 2018; 26:351-362. [PMID: 29452953 DOI: 10.1016/j.tim.2018.01.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/08/2018] [Accepted: 01/19/2018] [Indexed: 11/24/2022]
Abstract
Each of the three domains of life exhibits a unique motility structure: while Bacteria use flagella, Eukarya employ cilia, and Archaea swim using archaella. Since the new name for the archaeal motility structure was proposed, in 2012, a significant amount of new data on the regulation of transcription of archaella operons, the structure and function of archaellum subunits, their interactions, and cryo-EM data on in situ archaellum complexes in whole cells have been obtained. These data support the notion that the archaellum is evolutionary and structurally unrelated to the flagellum, but instead is related to archaeal and bacterial type IV pili and emphasize that it is a motility structure unique to the Archaea.
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Affiliation(s)
- Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II - Microbiology, University of Freiburg, 79104 Freiburg, Germany.
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
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29
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Chaudhury P, Quax TEF, Albers SV. Versatile cell surface structures of archaea. Mol Microbiol 2017; 107:298-311. [PMID: 29194812 DOI: 10.1111/mmi.13889] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2017] [Indexed: 11/27/2022]
Abstract
Archaea are ubiquitously present in nature and colonize environments with broadly varying growth conditions. Several surface appendages support their colonization of new habitats. A hallmark of archaea seems to be the high abundance of type IV pili (T4P). However, some unique non T4 filaments are present in a number of archaeal species. Archaeal surface structures can mediate different processes such as cellular surface adhesion, DNA exchange, motility and biofilm formation and represent an initial attachment site for infecting viruses. In addition to the functionally characterized archaeal T4P, archaeal genomes encode a large number of T4P components that might form yet undiscovered surface structures with novel functions. In this review, we summarize recent advancement in structural and functional characterizations of known archaeal surface structures and highlight the diverse processes in which they play a role.
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Affiliation(s)
- Paushali Chaudhury
- Institute of Biology II, Molecular Biology of Archaea, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Tessa E F Quax
- Institute of Biology II, Molecular Biology of Archaea, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Sonja-Verena Albers
- Institute of Biology II, Molecular Biology of Archaea, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
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30
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Wang F, Burrage AM, Postel S, Clark RE, Orlova A, Sundberg EJ, Kearns DB, Egelman EH. A structural model of flagellar filament switching across multiple bacterial species. Nat Commun 2017; 8:960. [PMID: 29038601 PMCID: PMC5643327 DOI: 10.1038/s41467-017-01075-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/15/2017] [Indexed: 12/21/2022] Open
Abstract
The bacterial flagellar filament has long been studied to understand how a polymer composed of a single protein can switch between different supercoiled states with high cooperativity. Here we present near-atomic resolution cryo-EM structures for flagellar filaments from both Gram-positive Bacillus subtilis and Gram-negative Pseudomonas aeruginosa. Seven mutant flagellar filaments in B. subtilis and two in P. aeruginosa capture two different states of the filament. These reliable atomic models of both states reveal conserved molecular interactions in the interior of the filament among B. subtilis, P. aeruginosa and Salmonella enterica. Using the detailed information about the molecular interactions in two filament states, we successfully predict point mutations that shift the equilibrium between those two states. Further, we observe the dimerization of P. aeruginosa outer domains without any perturbation of the conserved interior of the filament. Our results give new insights into how the flagellin sequence has been "tuned" over evolution.Bacterial flagellar filaments are composed almost entirely of a single protein-flagellin-which can switch between different supercoiled states in a highly cooperative manner. Here the authors present near-atomic resolution cryo-EM structures of nine flagellar filaments, and begin to shed light on the molecular basis of filament switching.
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Affiliation(s)
- Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Andrew M Burrage
- Department of Biology, Indiana University, Bloomington, IN, 47305, USA
| | - Sandra Postel
- Institute of Human Virology and University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Reece E Clark
- Department of Biology, Indiana University, Bloomington, IN, 47305, USA
| | - Albina Orlova
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Eric J Sundberg
- Institute of Human Virology and University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Departments of Medicine and of Microbiology & Immunology, University of Maryland School of Medicine, Baltimore, 21201, MD, USA
| | - Daniel B Kearns
- Department of Biology, Indiana University, Bloomington, IN, 47305, USA
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
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31
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Wlodawer A, Li M, Dauter Z. High-Resolution Cryo-EM Maps and Models: A Crystallographer's Perspective. Structure 2017; 25:1589-1597.e1. [PMID: 28867613 PMCID: PMC5657611 DOI: 10.1016/j.str.2017.07.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/17/2017] [Accepted: 07/26/2017] [Indexed: 12/22/2022]
Abstract
The appearance of ten high-resolution cryoelectron microscopy (cryo-EM) maps of proteins, ribosomes, and viruses was compared with the experimentally phased crystallographic electron density maps of four proteins. We found that maps calculated at a similar resolution by the two techniques are quite comparable in their appearance, although cryo-EM maps, even when sharpened, seem to be a little less detailed. An analysis of models fitted to the cryo-EM maps indicated the presence of significant problems in almost all of them, including incorrect geometry, clashes between atoms, and discrepancies between the map density and the fitted models. In particular, the treatment of the atomic displacement (B) factors was meaningless in almost all analyzed cryo-EM models. Stricter cryo-EM structure deposition standards and their better enforcement are needed.
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Affiliation(s)
- Alexander Wlodawer
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA.
| | - Mi Li
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA; Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Zbigniew Dauter
- Synchrotron Radiation Research Section, Macromolecular Crystallography Laboratory, NCI, Argonne National Laboratory, Argonne, IL 60439, USA
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32
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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] [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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33
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Egelman EH. Cryo-EM of bacterial pili and archaeal flagellar filaments. Curr Opin Struct Biol 2017; 46:31-37. [PMID: 28609682 DOI: 10.1016/j.sbi.2017.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 05/07/2017] [Accepted: 05/25/2017] [Indexed: 01/24/2023]
Abstract
Recent advances in cryo-electron microscopy (cryo-EM) have opened up the possibility that a large class of biological structures, helical polymers, may now be readily reconstructed at near-atomic resolution. This will have a huge impact, since most of these structures are unlikely to be crystallized. This review focuses on new cryo-EM studies involving three classes of bacterial pili (chaperone-usher, mating, and Type IV) as well as on archaeal flagellar filaments. While it has long been known that one domain within archaeal flagellar filaments is homologous to a domain within bacterial Type IV pilins, the new studies shed light on how homologous and even highly conserved subunits can pack together in different ways with only small changes in sequence.
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Affiliation(s)
- Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908-0733, United States.
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34
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Poweleit N, Ge P, Nguyen HH, Ogorzalek Loo RR, Gunsalus RP, Zhou ZH. CryoEM structure of the Methanospirillum hungatei archaellum reveals structural features distinct from the bacterial flagellum and type IV pilus. Nat Microbiol 2016; 2:16222. [PMID: 27922015 PMCID: PMC5695567 DOI: 10.1038/nmicrobiol.2016.222] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 10/07/2016] [Indexed: 11/08/2022]
Abstract
Archaea use flagella known as archaella-distinct both in protein composition and structure from bacterial flagella-to drive cell motility, but the structural basis of this function is unknown. Here, we report an atomic model of the archaella, based on the cryo electron microscopy (cryoEM) structure of the Methanospirillum hungatei archaellum at 3.4 Å resolution. Each archaellum contains ∼61,500 archaellin subunits organized into a curved helix with a diameter of 10 nm and average length of 10,000 nm. The tadpole-shaped archaellin monomer has two domains, a β-barrel domain and a long, mildly kinked α-helix tail. Our structure reveals multiple post-translational modifications to the archaella, including six O-linked glycans and an unusual N-linked modification. The extensive interactions among neighbouring archaellins explain how the long but thin archaellum maintains the structural integrity required for motility-driving rotation. These extensive inter-subunit interactions and the absence of a central pore in the archaellum distinguish it from both the bacterial flagellum and type IV pili.
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Affiliation(s)
- Nicole Poweleit
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California 90095, USA
- Electron Imaging Center for Nanomachines, California Nano Systems Institute, UCLA, Los Angeles (UCLA), Los Angeles, California 90095, USA
| | - Peng Ge
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California 90095, USA
- Electron Imaging Center for Nanomachines, California Nano Systems Institute, UCLA, Los Angeles (UCLA), Los Angeles, California 90095, USA
| | - Hong H. Nguyen
- Department of Chemistry and Biochemistry, UCLA, Los Angeles 90095, UCLA, Los Angeles (UCLA), Los Angeles, California 90095, USA
| | - Rachel R. Ogorzalek Loo
- Department of Chemistry and Biochemistry, UCLA, Los Angeles 90095, UCLA, Los Angeles (UCLA), Los Angeles, California 90095, USA
| | - Robert P. Gunsalus
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California 90095, USA
- The UCLA-DOE Institute, UCLA, Los Angeles, California 90095, USA
| | - Z. Hong Zhou
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, California 90095, USA
- Electron Imaging Center for Nanomachines, California Nano Systems Institute, UCLA, Los Angeles (UCLA), Los Angeles, California 90095, USA
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35
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Wirth R, Ugele M, Wanner G. Motility and Ultrastructure of Spirochaeta thermophila. Front Microbiol 2016; 7:1609. [PMID: 27790206 PMCID: PMC5064287 DOI: 10.3389/fmicb.2016.01609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/26/2016] [Indexed: 12/19/2022] Open
Abstract
We analyze here for the first time the swimming behavior of a thermophilic, strictly anaerobic Spirochete, namely Spirochaeta thermophila using high temperature light microscopy. Our data show that S. thermophila very rapidly can change its morphology during swimming, resulting in cells appearing nearly linear, in cells possessing three different spiral forms, and in cells being linear at one end and spiral at the other end. In addition cells can rapidly bend by up to 180°, with their ends coming into close contact. We combine electron with light microscopy to explain these various cell morphologies. Swimming speeds for cells with the various morphologies did not differ significantly: the average speed was 33 (± 8) μm/s, with minimal and maximal speeds of 19 and 59 μm/s, respectively. Addition of gelling agents like polyvinylpyrrolidone or methyl cellulose to the growth medium resulted in lower and not higher swimming speeds, arguing against the idea that the highly unusual cell body plan of S. thermophila enables cells to swim more efficiently in gel-like habitats.
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Affiliation(s)
- Reinhard Wirth
- Faculty of Biology, University of Regensburg Regensburg, Germany
| | - Matthias Ugele
- In-Vitro DX and Bioscience, Department of Strategy and Innovation, Siemens Healthcare GmbH Erlangen, Germany
| | - Gerhard Wanner
- Department of Biology I, Ludwig-Maximilian-University Munich, Germany
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36
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Structure of the Neisseria meningitidis Type IV pilus. Nat Commun 2016; 7:13015. [PMID: 27698424 PMCID: PMC5059446 DOI: 10.1038/ncomms13015] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/25/2016] [Indexed: 02/04/2023] Open
Abstract
Neisseria meningitidis use Type IV pili (T4P) to adhere to endothelial cells and breach the blood brain barrier, causing cause fatal meningitis. T4P are multifunctional polymers of the major pilin protein, which share a conserved hydrophobic N terminus that is a curved extended α-helix, α1, in X-ray crystal structures. Here we report a 1.44 Å crystal structure of the N. meningitidis major pilin PilE and a ∼6 Å cryo-electron microscopy reconstruction of the intact pilus, from which we built an atomic model for the filament. This structure reveals the molecular arrangement of the N-terminal α-helices in the filament core, including a melted central portion of α1 and a bridge of electron density consistent with a predicted salt bridge necessary for pilus assembly. This structure has important implications for understanding pilus biology. Type IV pili are present on a wide range of bacterial pathogens and mediate diverse functions. Here the authors report a high resolution crystal structure of the pilin subunit PilE, and a cryoEM reconstruction of the Type IV pilus filament from N. meningitidis that offer insight into pilus assembly and functions.
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