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van Wolferen M, Pulschen AA, Baum B, Gribaldo S, Albers SV. The cell biology of archaea. Nat Microbiol 2022; 7:1744-1755. [PMID: 36253512 PMCID: PMC7613921 DOI: 10.1038/s41564-022-01215-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/25/2022] [Indexed: 12/15/2022]
Abstract
The past decade has revealed the diversity and ubiquity of archaea in nature, with a growing number of studies highlighting their importance in ecology, biotechnology and even human health. Myriad lineages have been discovered, which expanded the phylogenetic breadth of archaea and revealed their central role in the evolutionary origins of eukaryotes. These discoveries, coupled with advances that enable the culturing and live imaging of archaeal cells under extreme environments, have underpinned a better understanding of their biology. In this Review we focus on the shape, internal organization and surface structures that are characteristic of archaeal cells as well as membrane remodelling, cell growth and division. We also highlight some of the technical challenges faced and discuss how new and improved technologies will help address many of the key unanswered questions.
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Affiliation(s)
- Marleen van Wolferen
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Buzz Baum
- Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, UK.
| | - Simonetta Gribaldo
- Evolutionary Biology of the Microbial Cell Unit, CNRS UMR2001, Department of Microbiology, Institute Pasteur, Paris, France.
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany.
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2
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Kontou A, Herman EK, Field MC, Dacks JB, Koumandou VL. Evolution of factors shaping the endoplasmic reticulum. Traffic 2022; 23:462-473. [PMID: 36040076 PMCID: PMC9804665 DOI: 10.1111/tra.12863] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 06/30/2022] [Accepted: 07/24/2022] [Indexed: 01/09/2023]
Abstract
Endomembrane system compartments are significant elements in virtually all eukaryotic cells, supporting functions including protein synthesis, post-translational modifications and protein/lipid targeting. In terms of membrane area the endoplasmic reticulum (ER) is the largest intracellular organelle, but the origins of proteins defining the organelle and the nature of lineage-specific modifications remain poorly studied. To understand the evolution of factors mediating ER morphology and function we report a comparative genomics analysis of experimentally characterized ER-associated proteins involved in maintaining ER structure. We find that reticulons, REEPs, atlastins, Ufe1p, Use1p, Dsl1p, TBC1D20, Yip3p and VAPs are highly conserved, suggesting an origin at least as early as the last eukaryotic common ancestor (LECA), although many of these proteins possess additional non-ER functions in modern eukaryotes. Secondary losses are common in individual species and in certain lineages, for example lunapark is missing from the Stramenopiles and the Alveolata. Lineage-specific innovations include protrudin, Caspr1, Arl6IP1, p180, NogoR, kinectin and CLIMP-63, which are restricted to the Opisthokonta. Hence, much of the machinery required to build and maintain the ER predates the LECA, but alternative strategies for the maintenance and elaboration of ER shape and function are present in modern eukaryotes. Moreover, experimental investigations for ER maintenance factors in diverse eukaryotes are expected to uncover novel mechanisms.
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Affiliation(s)
- Aspasia Kontou
- Genetics Laboratory, Department of BiotechnologyAgricultural University of AthensAthensGreece
| | - Emily K. Herman
- Division of Infectious Diseases, Department of MedicineUniversity of AlbertaEdmontonAlbertaCanada,Present address:
Department of Agricultural, Food and Nutritional Science, Faculty of Agricultural, Life and Environmental SciencesUniversity of AlbertaEdmontonAlbertaCanada
| | - Mark C. Field
- School of Life SciencesUniversity of DundeeDundeeUK,Biology CentreCzech Academy of SciencesČeské BudějoviceCzech Republic
| | - Joel B. Dacks
- Division of Infectious Diseases, Department of MedicineUniversity of AlbertaEdmontonAlbertaCanada,Biology CentreCzech Academy of SciencesČeské BudějoviceCzech Republic,Centre for Life's Origin and Evolution, Department of Genetics, Evolution and EnvironmentUniversity College of LondonLondonUK
| | - V. Lila Koumandou
- Genetics Laboratory, Department of BiotechnologyAgricultural University of AthensAthensGreece
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Abstract
The translocation of proteins across membranes is a fundamental cellular function. Bacteria have evolved a striking array of pathways for delivering proteins into or across cytoplasmic membranes and, when present, outer membranes. Translocated proteins can form part of the membrane landscape, reside in the periplasmic space situated between the inner and outer membranes of Gram-negative bacteria, deposit on the cell surface, or be released to the extracellular milieu or injected directly into target cells. One protein translocation system, the general secretory pathway, is conserved in all domains of life. A second, the twin-arginine translocation pathway, is also phylogenetically distributed among most bacteria and plant chloroplasts. While all cell types have evolved additional systems dedicated to the translocation of protein cargoes, the number of such systems in bacteria is now known to exceed nine. These dedicated protein translocation systems, which include the types 1 through 9 secretion systems (T1SSs-T9SSs), the chaperone-usher pathway, and type IV pilus system, are the subject of this review. Most of these systems were originally identified and have been extensively characterized in Gram-negative or diderm (two-membrane) species. It is now known that several of these systems also have been adapted to function in Gram-positive or monoderm (single-membrane) species, and at least one pathway is found only in monoderms. This review briefly summarizes the distinctive mechanistic and structural features of each dedicated pathway, as well as the shared properties, that together account for the broad biological diversity of protein translocation in bacteria.
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Affiliation(s)
- Peter J Christie
- Department of Microbiology and Molecular Genetics, McGovern Medical School, 6431 Fannin St., Houston, TX, USA.
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Beeby M, Ferreira JL, Tripp P, Albers SV, Mitchell DR. Propulsive nanomachines: the convergent evolution of archaella, flagella and cilia. FEMS Microbiol Rev 2020; 44:253-304. [DOI: 10.1093/femsre/fuaa006] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 03/06/2020] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
Echoing the repeated convergent evolution of flight and vision in large eukaryotes, propulsive swimming motility has evolved independently in microbes in each of the three domains of life. Filamentous appendages – archaella in Archaea, flagella in Bacteria and cilia in Eukaryotes – wave, whip or rotate to propel microbes, overcoming diffusion and enabling colonization of new environments. The implementations of the three propulsive nanomachines are distinct, however: archaella and flagella rotate, while cilia beat or wave; flagella and cilia assemble at their tips, while archaella assemble at their base; archaella and cilia use ATP for motility, while flagella use ion-motive force. These underlying differences reflect the tinkering required to evolve a molecular machine, in which pre-existing machines in the appropriate contexts were iteratively co-opted for new functions and whose origins are reflected in their resultant mechanisms. Contemporary homologies suggest that archaella evolved from a non-rotary pilus, flagella from a non-rotary appendage or secretion system, and cilia from a passive sensory structure. Here, we review the structure, assembly, mechanism and homologies of the three distinct solutions as a foundation to better understand how propulsive nanomachines evolved three times independently and to highlight principles of molecular evolution.
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Affiliation(s)
- Morgan Beeby
- Department of Life Sciences, Frankland Road, Imperial College of London, London, SW7 2AZ, UK
| | - Josie L Ferreira
- Department of Life Sciences, Frankland Road, Imperial College of London, London, SW7 2AZ, UK
| | - Patrick Tripp
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Schaenzlestrasse 1, 79211 Freiburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Schaenzlestrasse 1, 79211 Freiburg, Germany
| | - David R Mitchell
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
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The structure of the periplasmic FlaG-FlaF complex and its essential role for archaellar swimming motility. Nat Microbiol 2019; 5:216-225. [PMID: 31844299 DOI: 10.1038/s41564-019-0622-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 10/23/2019] [Indexed: 11/08/2022]
Abstract
Motility structures are vital in all three domains of life. In Archaea, motility is mediated by the archaellum, a rotating type IV pilus-like structure that is a unique nanomachine for swimming motility in nature. Whereas periplasmic FlaF binds the surface layer (S-layer), the structure, assembly and roles of other periplasmic components remain enigmatic, limiting our knowledge of the archaellum's functional interactions. Here, we find that the periplasmic protein FlaG and the association with its paralogue FlaF are essential for archaellation and motility. Therefore, we determine the crystal structure of Sulfolobus acidocaldarius soluble FlaG (sFlaG), which reveals a β-sandwich fold resembling the S-layer-interacting FlaF soluble domain (sFlaF). Furthermore, we solve the sFlaG2-sFlaF2 co-crystal structure, define its heterotetrameric complex in solution by small-angle X-ray scattering and find that mutations that disrupt the complex abolish motility. Interestingly, the sFlaF and sFlaG of Pyrococcus furiosus form a globular complex, whereas sFlaG alone forms a filament, indicating that FlaF can regulate FlaG filament assembly. Strikingly, Sulfolobus cells that lack the S-layer component bound by FlaF assemble archaella but cannot swim. These collective results support a model where a FlaG filament capped by a FlaG-FlaF complex anchors the archaellum to the S-layer to allow motility.
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Sharma A, Rani S, Goel M. Navigating the structure–function–evolutionary relationship of CsaA chaperone in archaea. Crit Rev Microbiol 2017; 44:274-289. [DOI: 10.1080/1040841x.2017.1357535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Archana Sharma
- Department of Biophysics, University of Delhi South Campus, New Delhi, India
| | - Shikha Rani
- Department of Biophysics, University of Delhi South Campus, New Delhi, India
| | - Manisha Goel
- Department of Biophysics, University of Delhi South Campus, New Delhi, India
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Hoppstock L, Trusch F, Lederer C, van West P, Koenneke M, Bayer P. NmPin from the marine thaumarchaeote Nitrosopumilus maritimus is an active membrane associated prolyl isomerase. BMC Biol 2016; 14:53. [PMID: 27349962 PMCID: PMC4922055 DOI: 10.1186/s12915-016-0274-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/14/2016] [Indexed: 12/01/2022] Open
Abstract
Background Peptidyl-prolyl isomerases (PPIases) are present in all forms of life and play a crucial role in protein folding and regulation. They catalyze the cis-trans isomerization of the peptide bond that precedes proline residues in numerous proteins. The parvulins, which is one family of PPIases, have been extensively investigated in several eukaryotes. However, nothing is known about their expression, function and localization in archaea. Results Here, we describe the endogenous expression, molecular structure, function and cellular localization of NmPin, a single-domain parvulin-type PPIase from Nitrosopumilus maritimus. This marine chemolithoautotrophic archaeon belongs to the globally abundant phylum Thaumarchaeota. Using high resolution NMR spectroscopy we demonstrate that the 3D structure of NmPin adopts a parvulin fold and confirmed its peptidyl-prolyl isomerase activity by protease-coupled assays and mutagenesis studies. A detailed topological analysis revealed a positively charged lysine-rich patch on the protein surface, which is conserved in all known parvulin sequences of thaumarchaeotes and targets NmPin to lipids in vitro. Immunofluorescence microscopy confirms that the protein is attached to the outer archaeal cell membrane in vivo. Transmission electron microscopy uncovered that NmPin has a uniform distribution at the membrane surface, which is correlated with a native cell shape of the prokaryote. Conclusion We present a novel solution structure of a catalytically active thaumarchaeal parvulin. Our results reveal that a lysine-rich patch in NmPin mediates membrane localization. These findings provide a model whereby NmPin is located between the archaeal membrane and the surface layer and hence suggest proteins of the S-layer as the key target substrates of this parvulin. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0274-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lukas Hoppstock
- Department of Structural and Medicinal Biochemistry, Centre for Medical Biotechnology, University of Duisburg-Essen, Universitätsstr. 1-4, 45141, Essen, Germany
| | - Franziska Trusch
- Aberdeen Oomycetes Laboratory, Institute of Medical Sciences, University of Aberdeen, Foresterhill, AB25 2ZD, Aberdeen, UK
| | - Christoph Lederer
- Department of Structural and Medicinal Biochemistry, Centre for Medical Biotechnology, University of Duisburg-Essen, Universitätsstr. 1-4, 45141, Essen, Germany
| | - Pieter van West
- Aberdeen Oomycetes Laboratory, Institute of Medical Sciences, University of Aberdeen, Foresterhill, AB25 2ZD, Aberdeen, UK
| | - Martin Koenneke
- Organic Geochemistry Group, MARUM Center for Marine Environmental Sciences, University of Bremen, Leobener Str. MARUM, 28359, Bremen, Germany
| | - Peter Bayer
- Department of Structural and Medicinal Biochemistry, Centre for Medical Biotechnology, University of Duisburg-Essen, Universitätsstr. 1-4, 45141, Essen, Germany.
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Coburger I, Schaub Y, Roeser D, Hardes K, Maeder P, Klee N, Steinmetzer T, Imhof D, Diederich WE, Than ME. Identification of inhibitors of the transmembrane protease FlaK of Methanococcus maripaludis. Microbiologyopen 2016; 5:637-46. [PMID: 27038342 PMCID: PMC4985597 DOI: 10.1002/mbo3.358] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 02/23/2016] [Accepted: 03/07/2016] [Indexed: 01/17/2023] Open
Abstract
GxGD‐type intramembrane cleaving proteases (I‐CLiPs) form a family of proteolytic enzymes that feature an aspartate‐based catalytic mechanism. Yet, they structurally and functionally largely differ from the classical pepsin‐like aspartic proteases. Among them are the archaeal enzyme FlaK, processing its substrate FlaB2 during the formation of flagella and γ‐secretase, which is centrally involved in the etiology of the neurodegenerative Alzheimer's disease. We developed an optimized activity assay for FlaK and based on screening of a small in‐house library and chemical synthesis, we identified compound 9 as the first inhibitor of this enzyme. Our results show that this intramembrane protease differs from classical pepsin‐like aspartic proteases and give insights into the substrate recognition of this enzyme. By providing the needed tools to further study the enzymatic cycle of FlaK, our results also enable further studies towards a functional understanding of other GxGD‐type I‐CLiPs.
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Affiliation(s)
- Ina Coburger
- Leibniz Institute on Aging (FLI), Protein Crystallography Group, Beutenbergstr. 11, Jena, 07745, Germany
| | - Yvonne Schaub
- Leibniz Institute on Aging (FLI), Protein Crystallography Group, Beutenbergstr. 11, Jena, 07745, Germany
| | - Dirk Roeser
- Leibniz Institute on Aging (FLI), Protein Crystallography Group, Beutenbergstr. 11, Jena, 07745, Germany
| | - Kornelia Hardes
- Department of Pharmaceutical Chemistry, Philipps University Marburg, Marbacher Weg 6, Marburg, 35032, Germany
| | - Patrick Maeder
- Department of Pharmaceutical Chemistry, Philipps University Marburg, Marbacher Weg 6, Marburg, 35032, Germany
| | - Nina Klee
- Department of Pharmaceutical Chemistry, Philipps University Marburg, Marbacher Weg 6, Marburg, 35032, Germany
| | - Torsten Steinmetzer
- Department of Pharmaceutical Chemistry, Philipps University Marburg, Marbacher Weg 6, Marburg, 35032, Germany
| | - Diana Imhof
- Institute of Pharmacy, Pharmaceutical Chemistry I, University of Bonn, Brühler Str. 7, Bonn, 53119, Germany
| | - Wibke E Diederich
- Department of Pharmaceutical Chemistry, Philipps University Marburg, Marbacher Weg 6, Marburg, 35032, Germany
| | - Manuel E Than
- Leibniz Institute on Aging (FLI), Protein Crystallography Group, Beutenbergstr. 11, Jena, 07745, Germany
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9
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Makarova KS, Galperin MY, Koonin EV. Comparative genomic analysis of evolutionarily conserved but functionally uncharacterized membrane proteins in archaea: Prediction of novel components of secretion, membrane remodeling and glycosylation systems. Biochimie 2015; 118:302-12. [PMID: 25583072 PMCID: PMC5898192 DOI: 10.1016/j.biochi.2015.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/02/2015] [Indexed: 01/03/2023]
Abstract
A systematic comparative genomic analysis of all archaeal membrane proteins that have been projected to the last archaeal common ancestor gene set led to the identification of several novel components of predicted secretion, membrane remodeling, and protein glycosylation systems. Among other findings, most crenarchaea have been shown to encode highly diverged orthologs of the membrane insertase YidC, which is nearly universal in bacteria, eukaryotes, and euryarchaea. We also identified a vast family of archaeal proteins, including the C-terminal domain of N-glycosylation protein AglD, as membrane flippases homologous to the flippase domain of bacterial multipeptide resistance factor MprF, a bifunctional lysylphosphatidylglycerol synthase and flippase. Additionally, several proteins were predicted to function as membrane transporters. The results of this work, combined with our previous analyses, reveal an unexpected diversity of putative archaeal membrane-associated functional systems that remain to be functionally characterized. A more general conclusion from this work is that the currently available collection of archaeal (and bacterial) genomes could be sufficient to identify (almost) all widespread functional modules and develop experimentally testable predictions of their functions.
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Affiliation(s)
- Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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Soo E, Rudrappa D, Blum P. Membrane Association and Catabolite Repression of the Sulfolobus solfataricus α-Amylase. Microorganisms 2015; 3:567-87. [PMID: 27682106 PMCID: PMC5023256 DOI: 10.3390/microorganisms3030567] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/10/2015] [Accepted: 09/11/2015] [Indexed: 11/16/2022] Open
Abstract
Sulfolobus solfataricus is a thermoacidophilic member of the archaea whose envelope consists of an ether-linked lipid monolayer surrounded by a protein S-layer. Protein translocation across this envelope must accommodate a steep proton gradient that is subject to temperature extremes. To better understand this process in vivo, studies were conducted on the S. solfataricus glycosyl hydrolyase family 57 α-Amylase (AmyA). Cell lines harboring site specific modifications of the amyA promoter and AmyA structural domains were created by gene replacement using markerless exchange and characterized by Western blot, enzyme assay and culture-based analysis. Fusion of amyA to the malAp promoter overcame amyAp-mediated regulatory responses to media composition including glucose and amino acid repression implicating action act at the level of transcription. Deletion of the AmyA Class II N-terminal signal peptide blocked protein secretion and intracellular protein accumulation. Deletion analysis of a conserved bipartite C-terminal motif consisting of a hydrophobic region followed by several charged residues indicated the charged residues played an essential role in membrane-association but not protein secretion. Mutants lacking the C-terminal bipartite motif exhibited reduced growth rates on starch as the sole carbon and energy source; therefore, association of AmyA with the membrane improves carbohydrate utilization. Widespread occurrence of this motif in other secreted proteins of S. solfataricus and of related Crenarchaeota suggests protein association with membranes is a general trait used by these organisms to influence external processes.
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Affiliation(s)
- Edith Soo
- School of Biological Sciences, University of Nebraska-Lincoln, 1901 Vine Street, Lincoln 68588, NE, USA.
| | - Deepak Rudrappa
- School of Biological Sciences, University of Nebraska-Lincoln, 1901 Vine Street, Lincoln 68588, NE, USA.
| | - Paul Blum
- School of Biological Sciences, University of Nebraska-Lincoln, 1901 Vine Street, Lincoln 68588, NE, USA.
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Leon DR, Ytterberg AJ, Boontheung P, Kim U, Loo JA, Gunsalus RP, Ogorzalek Loo RR. Mining proteomic data to expose protein modifications in Methanosarcina mazei strain Gö1. Front Microbiol 2015; 6:149. [PMID: 25798134 PMCID: PMC4350412 DOI: 10.3389/fmicb.2015.00149] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 02/09/2015] [Indexed: 12/11/2022] Open
Abstract
Proteomic tools identify constituents of complex mixtures, often delivering long lists of identified proteins. The high-throughput methods excel at matching tandem mass spectrometry data to spectra predicted from sequence databases. Unassigned mass spectra are ignored, but could, in principle, provide valuable information on unanticipated modifications and improve protein annotations while consuming limited quantities of material. Strategies to "mine" information from these discards are presented, along with discussion of features that, when present, provide strong support for modifications. In this study we mined LC-MS/MS datasets of proteolytically-digested concanavalin A pull down fractions from Methanosarcina mazei Gö1 cell lysates. Analyses identified 154 proteins. Many of the observed proteins displayed post-translationally modified forms, including O-formylated and methyl-esterified segments that appear biologically relevant (i.e., not artifacts of sample handling). Interesting cleavages and modifications (e.g., S-cyanylation and trimethylation) were observed near catalytic sites of methanogenesis enzymes. Of 31 Methanosarcina protein N-termini recovered by concanavalin A binding or from a previous study, only M. mazei S-layer protein MM1976 and its M. acetivorans C2A orthologue, MA0829, underwent signal peptide excision. Experimental results contrast with predictions from algorithms SignalP 3.0 and Exprot, which were found to over-predict the presence of signal peptides. Proteins MM0002, MM0716, MM1364, and MM1976 were found to be glycosylated, and employing chromatography tailored specifically for glycopeptides will likely reveal more. This study supplements limited, existing experimental datasets of mature archaeal N-termini, including presence or absence of signal peptides, translation initiation sites, and other processing. Methanosarcina surface and membrane proteins are richly modified.
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Affiliation(s)
- Deborah R Leon
- Department of Chemistry and Biochemistry, University of California, Los Angeles Los Angeles, CA, USA
| | - A Jimmy Ytterberg
- Department of Chemistry and Biochemistry, University of California, Los Angeles Los Angeles, CA, USA
| | - Pinmanee Boontheung
- Department of Chemistry and Biochemistry, University of California, Los Angeles Los Angeles, CA, USA
| | - Unmi Kim
- Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles Los Angeles, CA, USA
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California, Los Angeles Los Angeles, CA, USA ; Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles Los Angeles, CA, USA ; UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles Los Angeles, CA, USA
| | - Robert P Gunsalus
- Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles Los Angeles, CA, USA ; UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles Los Angeles, CA, USA
| | - Rachel R Ogorzalek Loo
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles Los Angeles, CA, USA ; UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles Los Angeles, CA, USA
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Giménez MI, Cerletti M, De Castro RE. Archaeal membrane-associated proteases: insights on Haloferax volcanii and other haloarchaea. Front Microbiol 2015; 6:39. [PMID: 25774151 PMCID: PMC4343526 DOI: 10.3389/fmicb.2015.00039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 01/12/2015] [Indexed: 11/17/2022] Open
Abstract
The function of membrane proteases range from general house-keeping to regulation of cellular processes. Although the biological role of these enzymes in archaea is poorly understood, some of them are implicated in the biogenesis of the archaeal cell envelope and surface structures. The membrane-bound ATP-dependent Lon protease is essential for cell viability and affects membrane carotenoid content in Haloferax volcanii. At least two different proteases are needed in this archaeon to accomplish the posttranslational modifications of the S-layer glycoprotein. The rhomboid protease RhoII is involved in the N-glycosylation of the S-layer protein with a sulfoquinovose-containing oligosaccharide while archaeosortase ArtA mediates the proteolytic processing coupled-lipid modification of this glycoprotein facilitating its attachment to the archaeal cell surface. Interestingly, two different signal peptidase I homologs exist in H. volcanii, Sec11a and Sec11b, which likely play distinct physiological roles. Type IV prepilin peptidase PibD processes flagellin/pilin precursors, being essential for the biogenesis and function of the archaellum and other cell surface structures in H. volcanii.
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Affiliation(s)
- María I Giménez
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Consejo Nacional de Investigaciones Científicas y Técnicas Mar del Plata, Argentina
| | - Micaela Cerletti
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Consejo Nacional de Investigaciones Científicas y Técnicas Mar del Plata, Argentina
| | - Rosana E De Castro
- Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Consejo Nacional de Investigaciones Científicas y Técnicas Mar del Plata, Argentina
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13
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Rutz C, Klein W, Schülein R. N-Terminal Signal Peptides of G Protein-Coupled Receptors. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 132:267-87. [DOI: 10.1016/bs.pmbts.2015.03.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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14
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Feng J, Wang J, Zhang Y, Du X, Xu Z, Wu Y, Tang W, Li M, Tang B, Tang XF. Proteomic analysis of the secretome of haloarchaeon Natrinema sp. J7-2. J Proteome Res 2014; 13:1248-58. [PMID: 24512091 DOI: 10.1021/pr400728x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although in silico predictions have revealed that haloarchaea can be distinguished from other organisms in that the Tat pathway is used more extensively than the Sec pathway for haloarchaeal protein secretion, only a few haloarchaeal-secreted proteins have been experimentally confirmed. Here, the culture supernatant and membrane fraction of the haloarchaeon Natrinema sp. J7-2 grown at 23% salt concentration were subjected to RPLC-ESI-MS/MS analysis. In total, 46 predicted Tat substrates, 14 predicted Sec substrates, and 3 class III signal peptide-bearing proteins were detected. Approximately 65% of the detected Tat substrates contain lipoboxes, emphasizing the role of the Tat pathway in haloarchaeal lipoprotein secretion. Most of the detected Tat substrates are extracellular substrate (solute)-binding proteins and redox proteins. Despite the small number of Sec substrates, two of them, a cell surface glycoprotein and a putative lipoprotein carrier protein, were identified to be high-abundance secreted proteins. While limited proteins were detected in the culture supernatant, most of the secreted proteins were found in the membrane fraction. The anchoring of secreted proteins to the cell surface via a lipobox or a PGF-CTERM seems to be an adaptation strategy of haloarchaea to handle the harsh extracellular environment. Additionally, ∼15% of the integral membrane proteins (IMPs) detected in the membrane fraction possess putative Sec signal peptides or signal anchors, implying that the Sec pathway is important for membrane insertion of IMPs. This is the first report to describe the experimental secretome of haloarchaea and provide new information for better understanding of haloarchaeal protein secretion patterns.
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Affiliation(s)
- Jie Feng
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University , Wuhan 430072, China
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Fu HY, Yi HP, Lu YH, Yang CS. Insight into a single halobacterium using a dual-bacteriorhodopsin system with different functionally optimized pH ranges to cope with periplasmic pH changes associated with continuous light illumination. Mol Microbiol 2013; 88:551-61. [DOI: 10.1111/mmi.12208] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Hsu-Yuan Fu
- Department of Biochemical Science and Technology; College of Life Science; National Taiwan University; No. 1, Sec. 4, Roosevelt Rd. Taipei Taiwan 10617
| | - Hsiu-Ping Yi
- Department of Biochemical Science and Technology; College of Life Science; National Taiwan University; No. 1, Sec. 4, Roosevelt Rd. Taipei Taiwan 10617
| | - Yen-Hsu Lu
- Department of Biochemical Science and Technology; College of Life Science; National Taiwan University; No. 1, Sec. 4, Roosevelt Rd. Taipei Taiwan 10617
| | - Chii-Shen Yang
- Department of Biochemical Science and Technology; College of Life Science; National Taiwan University; No. 1, Sec. 4, Roosevelt Rd. Taipei Taiwan 10617
- Institute of Biotechnology; College of Bio-Resources and Agriculture; National Taiwan University; No. 1, Sec. 4, Roosevelt Rd. Taipei Taiwan 10617
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Archaea in symbioses. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2012; 2012:596846. [PMID: 23326206 PMCID: PMC3544247 DOI: 10.1155/2012/596846] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 11/19/2012] [Indexed: 12/13/2022]
Abstract
During the last few years, the analysis of microbial diversity in various habitats greatly increased our knowledge on the kingdom Archaea. At the same time, we became aware of the multiple ways in which Archaea may interact with each other and with organisms of other kingdoms. The large group of euryarchaeal methanogens and their methane oxidizing relatives, in particular, take part in essential steps of the global methane cycle. Both of these processes, which are in reverse to each other, are partially conducted in a symbiotic interaction with different partners, either ciliates and xylophagous animals or sulfate reducing bacteria. Other symbiotic interactions are mostly of unknown ecological significance but depend on highly specific mechanisms. This paper will give an overview on interactions between Archaea and other organisms and will point out the ecological relevance of these symbiotic processes, as long as these have been already recognized.
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Voigt B, Hieu CX, Hempel K, Becher D, Schlüter R, Teeling H, Glöckner FO, Amann R, Hecker M, Schweder T. Cell surface proteome of the marine planctomycete Rhodopirellula baltica. Proteomics 2012; 12:1781-91. [PMID: 22623273 DOI: 10.1002/pmic.201100512] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The surface proteome (surfaceome) of the marine planctomycete Rhodopirellula baltica SH1(T) was studied using a biotinylation and a proteinase K approach combined with SDS-PAGE and mass spectrometry. 52 of the proteins identified in both approaches could be assigned to the group of potential surface proteins. Among them are some high molecular weight proteins, potentially involved in cell-cell attachment, that contain domains shown before to be typical for surface proteins like cadherin/dockerin domains, a bacterial adhesion domain or the fasciclin domain. The identification of proteins with enzymatic functions in the R. baltica surfaceome provides further clues for the suggestion that some degradative enzymes may be anchored onto the cell surface. YTV proteins, which have been earlier supposed to be components of the proteinaceous cell wall of R. baltica, were detected in the surface proteome. Additionally, 8 proteins with a novel protein structure combining a conserved type IV pilin/N-methylation domain and a planctomycete-typical DUF1559 domain were identified.
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Affiliation(s)
- Birgit Voigt
- Institute for Microbiology, Ernst-Moritz-Arndt-University, Greifswald, Germany
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18
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Abstract
The acidophilic archaeons are a group of single-celled microorganisms that flourish in hot acid springs (usually pH < 3) but maintain their internal pH near neutral. Although there is a lack of direct evidence, the abundance of sugar modifications on the cell surface has been suggested to provide the acidophiles with protection against proton invasion. In this study, a hydroxyl (OH)-rich polymer brush layer was prepared to mimic the OH-rich sugar coating. Using a novel pH-sensitive dithioacetal molecule as a probe, we studied the proton-resisting property and found that a 10-nm-thick polymer layer was able to raise the pH from 1.0 to > 5.0, indicating that the densely packed OH-rich layer is a proton shelter. As strong evidence for the role of sugar coatings as proton barriers, this biomimetic study provides insight into evolutionary biology, and the results also could be expanded for the development of biocompatible anti-acid materials.
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Matarazzo F, Ribeiro AC, Faveri M, Taddei C, Martinez MB, Mayer MPA. The domain Archaea in human mucosal surfaces. Clin Microbiol Infect 2012; 18:834-40. [PMID: 22827611 DOI: 10.1111/j.1469-0691.2012.03958.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Archaea present distinct features from bacteria and eukaryotes, and thus constitute one of the branches of the phylogenetic tree of life. Members of this domain colonize distinct niches in the human body, arranged in complex communities, especially in the intestines and the oral cavity. The diversity of archaea within these niches is limited to a few phylotypes, constituted in particular by methane-producing archaeal organisms. Although they are possibly symbionts, methanogens may play a role in the establishment of mucosal diseases by favouring the growth of certain bacterial groups.
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Affiliation(s)
- F Matarazzo
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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20
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Cai L, Zhao D, Hou J, Wu J, Cai S, Dassarma P, Xiang H. Cellular and organellar membrane-associated proteins in haloarchaea: Perspectives on the physiological significance and biotechnological applications. SCIENCE CHINA-LIFE SCIENCES 2012; 55:404-14. [DOI: 10.1007/s11427-012-4321-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Accepted: 04/15/2012] [Indexed: 11/24/2022]
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21
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Siebers B, Zaparty M, Raddatz G, Tjaden B, Albers SV, Bell SD, Blombach F, Kletzin A, Kyrpides N, Lanz C, Plagens A, Rampp M, Rosinus A, von Jan M, Makarova KS, Klenk HP, Schuster SC, Hensel R. The complete genome sequence of Thermoproteus tenax: a physiologically versatile member of the Crenarchaeota. PLoS One 2011; 6:e24222. [PMID: 22003381 PMCID: PMC3189178 DOI: 10.1371/journal.pone.0024222] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 08/08/2011] [Indexed: 11/18/2022] Open
Abstract
Here, we report on the complete genome sequence of the hyperthermophilic Crenarchaeum Thermoproteus tenax (strain Kra1, DSM 2078T) a type strain of the crenarchaeotal order Thermoproteales. Its circular 1.84-megabase genome harbors no extrachromosomal elements and 2,051 open reading frames are identified, covering 90.6% of the complete sequence, which represents a high coding density. Derived from the gene content, T. tenax is a representative member of the Crenarchaeota. The organism is strictly anaerobic and sulfur-dependent with optimal growth at 86°C and pH 5.6. One particular feature is the great metabolic versatility, which is not accompanied by a distinct increase of genome size or information density as compared to other Crenarchaeota. T. tenax is able to grow chemolithoautotrophically (CO2/H2) as well as chemoorganoheterotrophically in presence of various organic substrates. All pathways for synthesizing the 20 proteinogenic amino acids are present. In addition, two presumably complete gene sets for NADH:quinone oxidoreductase (complex I) were identified in the genome and there is evidence that either NADH or reduced ferredoxin might serve as electron donor. Beside the typical archaeal A0A1-ATP synthase, a membrane-bound pyrophosphatase is found, which might contribute to energy conservation. Surprisingly, all genes required for dissimilatory sulfate reduction are present, which is confirmed by growth experiments. Mentionable is furthermore, the presence of two proteins (ParA family ATPase, actin-like protein) that might be involved in cell division in Thermoproteales, where the ESCRT system is absent, and of genes involved in genetic competence (DprA, ComF) that is so far unique within Archaea.
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Affiliation(s)
- Bettina Siebers
- Faculty of Chemistry, Biofilm Centre, Molecular Enzyme Technology and Biochemistry, University of Duisburg-Essen, Essen, Germany
- * E-mail: (BS); (MZ)
| | - Melanie Zaparty
- Institute for Molecular and Cellular Anatomy, University of Regensburg, Regensburg, Germany
- * E-mail: (BS); (MZ)
| | - Guenter Raddatz
- Max-Planck-Institute for Biological Cybernetics, Tübingen, Germany
| | - Britta Tjaden
- Prokaryotic RNA Biology, Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
| | - Steve D. Bell
- Sir William Dunn School of Pathology, Oxford University, Oxford, United Kingdom
| | - Fabian Blombach
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
| | - Arnulf Kletzin
- Institute of Microbiology and Genetics, Technical University Darmstadt, Darmstadt, Germany
| | - Nikos Kyrpides
- DOE Joint Genome Institute, Walnut Creek, California, United States of America
| | - Christa Lanz
- Genome Centre, Max-Planck-Institute for Developmental Biology, Tuebingen, Germany
| | - André Plagens
- Prokaryotic RNA Biology, Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
| | - Markus Rampp
- Computer Centre Garching of the Max-Planck-Society (RZG), Max-Planck-Institute for Plasma Physics, München, Germany
| | - Andrea Rosinus
- Genome Centre, Max-Planck-Institute for Developmental Biology, Tuebingen, Germany
| | - Mathias von Jan
- DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Kira S. Makarova
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hans-Peter Klenk
- DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Stephan C. Schuster
- Center for Comparative Genomics and Bioinformatics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Reinhard Hensel
- Prokaryotic RNA Biology, Max-Planck-Institute for Terrestrial Microbiology, Marburg, Germany
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22
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Archaeal flagellar ATPase motor shows ATP-dependent hexameric assembly and activity stimulation by specific lipid binding. Biochem J 2011; 437:43-52. [PMID: 21506936 DOI: 10.1042/bj20110410] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Microbial motility frequently depends on flagella or type IV pili. Using recently developed archaeal genetic tools, archaeal flagella and its assembly machinery have been identified. Archaeal flagella are functionally similar to bacterial flagella and their assembly systems are homologous with type IV pili assembly systems of Gram-negative bacteria. Therefore elucidating their biochemistry may result in insights in both archaea and bacteria. FlaI, a critical cytoplasmic component of the archaeal flagella assembly system in Sulfolobus acidocaldarius, is a member of the type II/IV secretion system ATPase superfamily, and is proposed to be bi-functional in driving flagella assembly and movement. In the present study we show that purified FlaI is a Mn2+-dependent ATPase that binds MANT-ATP [2'-/3'-O-(N'- methylanthraniloyl)adenosine-5'-O-triphosphate] with a high affinity and hydrolyses ATP in a co-operative manner. FlaI has an optimum pH and temperature of 6.5 and 75 °C for ATP hydrolysis. Remarkably, archaeal, but not bacterial, lipids stimulated the ATPase activity of FlaI 3-4-fold. Analytical gel filtration indicated that FlaI undergoes nucleotide-dependent oligomerization. Furthermore, SAXS (small-angle X-ray scattering) analysis revealed an ATP-dependent hexamerization of FlaI in solution. The results of the present study report the first detailed biochemical analyses of the motor protein of an archaeal flagellum.
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23
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Jiang X, Fares MA. Functional Diversification of the Twin-Arginine Translocation Pathway Mediates the Emergence of Novel Ecological Adaptations. Mol Biol Evol 2011; 28:3183-93. [DOI: 10.1093/molbev/msr154] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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24
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Abstract
Since their discovery in the early 1980s, viruses that infect the third domain of life, the Archaea, have captivated our attention because of their virions' unusual morphologies and proteins, which lack homologues in extant databases. Moreover, the life cycles of these viruses have unusual features, as revealed by the recent discovery of a novel virus egress mechanism that involves the formation of specific pyramidal structures on the host cell surface. The available data elucidate the particular nature of the archaeal virosphere and shed light on questions concerning the origin and evolution of viruses and cells. In this review, we summarize the current knowledge of archeoviruses, their interaction with hosts and plasmids and their role in the evolution of life.
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Affiliation(s)
- Mery Pina
- Institut Pasteur, Molecular Biology of the Gene in Extremophiles Unit, Paris, France
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25
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Abstract
Motility is a common behaviour in prokaryotes. Both bacteria and archaea use flagella for swimming motility, but it has been well documented that structures of the flagellum from these two domains of life are completely different, although they contribute to a similar function. Interestingly, information available to date has revealed that structurally archaeal flagella are more similar to bacterial type IV pili rather than to bacterial flagella. With the increasing genome sequence information and advancement in genetic tools for archaea, identification of the components involved in the assembly of the archaeal flagellum is possible. A subset of these components shows similarities to components from type IV pilus-assembly systems. Whereas the molecular players involved in assembly of the archaeal flagellum are being identified, the mechanics and dynamics of the assembly of the archaeal flagellum have yet to be established. Recent computational analysis in our laboratory has identified conserved highly charged loop regions within one of the core proteins of the flagellum, the membrane integral protein FlaJ, and predicted that these are involved in the interaction with the assembly ATPase FlaI. Interestingly, considerable variation was found among the loops of FlaJ from the two major subkingdoms of archaea, the Euryarchaeota and the Crenarchaeota. Understanding the assembly pathway and creating an interaction map of the molecular players in the archaeal flagellum will shed light on the details of the assembly and also the evolutionary relationship to the bacterial type IV pili-assembly systems.
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Van Gerven N, Waksman G, Remaut H. Pili and flagella biology, structure, and biotechnological applications. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 103:21-72. [PMID: 21999994 DOI: 10.1016/b978-0-12-415906-8.00005-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Bacteria and Archaea expose on their outer surfaces a variety of thread-like proteinaceous organelles with which they interact with their environments. These structures are repetitive assemblies of covalently or non-covalently linked protein subunits, organized into filamentous polymers known as pili ("hair"), flagella ("whips") or injectisomes ("needles"). They serve different roles in cell motility, adhesion and host invasion, protein and DNA secretion and uptake, conductance, or cellular encapsulation. Here we describe the functional, morphological and genetic diversity of these bacterial filamentous protein structures. The organized, multi-copy build-up and/or the natural function of pili and flagella have lead to their biotechnological application as display and secretion tools, as therapeutic targets or as molecular motors. We review the documented and potential technological exploitation of bacterial surface filaments in light of their structural and functional traits.
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Affiliation(s)
- Nani Van Gerven
- Structural & Molecular Microbiology, VIB/Vrije Universiteit Brussel, Brussels, Belgium
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27
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C-terminal domain residues important for secretion and attachment of RgpB in Porphyromonas gingivalis. J Bacteriol 2010; 193:132-42. [PMID: 20971915 DOI: 10.1128/jb.00773-10] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Porphyromonas gingivalis, a periodontal pathogen, expresses a group of surface proteins with a common C-terminal domain (CTD) that are exported by a novel secretion system to the surface, where they are covalently attached. Using RgpB as a model CTD protein, we have produced a series of site-directed mutations in the CTD sequence at conserved residues and at residues that may be modified and, hence, surface attached. The mutant RgpB proteins were expressed in a P. gingivalis host lacking functional RgpB and RgpA Arg-specific proteases. The RgpB mutants produced were Y674F, Y674F Y718F, T675Q S679Q T682Q T684Q, T693Q, F695A, D696A, N698A, G699P, G716P, T724Q, T728Q T730Q, and K732Q and a protein with a deletion of residues 692 to 702 (Δ692-702). The mutants were characterized for cell-associated Arg-specific protease activity and for cellular distribution using anti-Rgp antibodies and Western blotting of culture fractions. All the mutants exhibited cell-associated Arg-specific activity similar to that of the positive control except for the D696A and Δ692-702 mutants. For all mutants, except D696A and Δ692-702, the RgpB proteins were found modified and attached to the cell surface, which was the same profile found in the positive-control strain. Only trace amounts of the precursor form of the Δ692-702 mutant were detected in the outer membrane, with none detected in the periplasm or culture fluid although cell transcript levels were normal. The results suggest that residues 692 to 702 of the CTD, in particular, residue D696, have an important role in the attachment of RgpB at the cell surface and that without attachment secretion does not occur.
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Biosynthesis and role of N-linked glycosylation in cell surface structures of archaea with a focus on flagella and s layers. Int J Microbiol 2010; 2010:470138. [PMID: 20976295 PMCID: PMC2952790 DOI: 10.1155/2010/470138] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 08/01/2010] [Indexed: 11/17/2022] Open
Abstract
The genetics and biochemistry of the N-linked glycosylation system of Archaea have been investigated over the past 5 years using flagellins and S layers as reporter proteins in the model organisms, Methanococcus voltae, Methanococcus maripaludis, and Haloferax volcanii. Structures of archaeal N-linked glycans have indicated a variety of linking sugars as well as unique sugar components. In M. voltae, M. maripaludis, and H. volcanii, a number of archaeal glycosylation genes (agl) have been identified by deletion and complementation studies. These include many of the glycosyltransferases and the oligosaccharyltransferase needed to assemble the glycans as well as some of the genes encoding enzymes required for the biosynthesis of the sugars themselves. The N-linked glycosylation system is not essential for any of M. voltae, M. maripaludis, or H. volcanii, as demonstrated by the successful isolation of mutants carrying deletions in the oligosaccharyltransferase gene aglB (a homologue of the eukaryotic Stt3 subunit of the oligosaccharyltransferase complex). However, mutations that affect the glycan structure have serious effects on both flagellation and S layer function.
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29
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Bohnsack MT, Schleiff E. The evolution of protein targeting and translocation systems. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:1115-30. [DOI: 10.1016/j.bbamcr.2010.06.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Revised: 05/26/2010] [Accepted: 06/11/2010] [Indexed: 11/28/2022]
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30
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Identification of various substrate-binding proteins of the hyperthermophylic archaeon Aeropyrum pernix K1. World J Microbiol Biotechnol 2010. [DOI: 10.1007/s11274-010-0333-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Shaping the archaeal cell envelope. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2010; 2010:608243. [PMID: 20671907 PMCID: PMC2910488 DOI: 10.1155/2010/608243] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 05/29/2010] [Indexed: 12/12/2022]
Abstract
Although archaea have a similar cellular organization as other prokaryotes, the lipid composition of their membranes and their cell surface is unique. Here we discuss recent developments in our understanding of the archaeal protein secretion mechanisms, the assembly of macromolecular cell surface structures, and the release of S-layer-coated vesicles from the archaeal membrane.
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32
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Archaea signal recognition particle shows the way. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2010; 2010:485051. [PMID: 20672053 PMCID: PMC2905702 DOI: 10.1155/2010/485051] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 05/14/2010] [Indexed: 01/24/2023]
Abstract
Archaea SRP is composed of an SRP RNA molecule and two bound proteins named SRP19 and SRP54. Regulated by the binding and hydrolysis of guanosine triphosphates, the RNA-bound SRP54 protein transiently associates not only with the hydrophobic signal sequence as it emerges from the ribosomal exit tunnel, but also interacts with the membrane-associated SRP receptor (FtsY). Comparative analyses of the archaea genomes and their SRP component sequences, combined with structural and biochemical data, support a prominent role of the SRP RNA in the assembly and function of the archaea SRP. The 5e motif, which in eukaryotes binds a 72 kilodalton protein, is preserved in most archaea SRP RNAs despite the lack of an archaea SRP72 homolog. The primary function of the 5e region may be to serve as a hinge, strategically positioned between the small and large SRP domain, allowing the elongated SRP to bind simultaneously to distant ribosomal sites. SRP19, required in eukaryotes for initiating SRP assembly, appears to play a subordinate role in the archaea SRP or may be defunct. The N-terminal A region and a novel C-terminal R region of the archaea SRP receptor (FtsY) are strikingly diverse or absent even among the members of a taxonomic subgroup.
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33
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Goudenège D, Avner S, Lucchetti-Miganeh C, Barloy-Hubler F. CoBaltDB: Complete bacterial and archaeal orfeomes subcellular localization database and associated resources. BMC Microbiol 2010; 10:88. [PMID: 20331850 PMCID: PMC2850352 DOI: 10.1186/1471-2180-10-88] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 03/23/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The functions of proteins are strongly related to their localization in cell compartments (for example the cytoplasm or membranes) but the experimental determination of the sub-cellular localization of proteomes is laborious and expensive. A fast and low-cost alternative approach is in silico prediction, based on features of the protein primary sequences. However, biologists are confronted with a very large number of computational tools that use different methods that address various localization features with diverse specificities and sensitivities. As a result, exploiting these computer resources to predict protein localization accurately involves querying all tools and comparing every prediction output; this is a painstaking task. Therefore, we developed a comprehensive database, called CoBaltDB, that gathers all prediction outputs concerning complete prokaryotic proteomes. DESCRIPTION The current version of CoBaltDB integrates the results of 43 localization predictors for 784 complete bacterial and archaeal proteomes (2.548.292 proteins in total). CoBaltDB supplies a simple user-friendly interface for retrieving and exploring relevant information about predicted features (such as signal peptide cleavage sites and transmembrane segments). Data are organized into three work-sets ("specialized tools", "meta-tools" and "additional tools"). The database can be queried using the organism name, a locus tag or a list of locus tags and may be browsed using numerous graphical and text displays. CONCLUSIONS With its new functionalities, CoBaltDB is a novel powerful platform that provides easy access to the results of multiple localization tools and support for predicting prokaryotic protein localizations with higher confidence than previously possible. CoBaltDB is available at http://www.umr6026.univ-rennes1.fr/english/home/research/basic/software/cobalten.
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Affiliation(s)
- David Goudenège
- CNRS UMR 6026, ICM, Equipe B@SIC, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes, France
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34
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Martin W. Evolutionary origins of metabolic compartmentalization in eukaryotes. Philos Trans R Soc Lond B Biol Sci 2010; 365:847-55. [PMID: 20124349 PMCID: PMC2817231 DOI: 10.1098/rstb.2009.0252] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Many genes in eukaryotes are acquisitions from the free-living antecedents of chloroplasts and mitochondria. But there is no evolutionary 'homing device' that automatically directs the protein product of a transferred gene back to the organelle of its provenance. Instead, the products of genes acquired from endosymbionts can explore all targeting possibilities within the cell. They often replace pre-existing host genes, or even whole pathways. But the transfer of an enzymatic pathway from one compartment to another poses severe problems: over evolutionary time, the enzymes of the pathway acquire their targeting signals for the new compartment individually, not in unison. Until the whole pathway is established in the new compartment, newly routed individual enzymes are useless, and their genes will be lost through mutation. Here it is suggested that pathways attain novel compartmentation variants via a 'minor mistargeting' mechanism. If protein targeting in eukaryotic cells possesses enough imperfection such that small amounts of entire pathways continuously enter novel compartments, selectable units of biochemical function would exist in new compartments, and the genes could become selected. Dual-targeting of proteins is indeed very common within eukaryotic cells, suggesting that targeting variation required for this minor mistargeting mechanism to operate exists in nature.
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Affiliation(s)
- William Martin
- Institute of Botany III, University of Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
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Hydrophobically stabilized open state for the lateral gate of the Sec translocon. Proc Natl Acad Sci U S A 2010; 107:5399-404. [PMID: 20203009 DOI: 10.1073/pnas.0914752107] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Sec translocon is a central component of cellular pathways for protein translocation and membrane integration. Using both atomistic and coarse-grained molecular simulations, we investigate the conformational landscape of the translocon and explore the role of peptide substrates in the regulation of the translocation and integration pathways. Inclusion of a hydrophobic peptide substrate in the translocon stabilizes the opening of the lateral gate for membrane integration, whereas a hydrophilic peptide substrate favors the closed lateral gate conformation. The relative orientation of the plug moiety and a peptide substrate within the translocon channel is similarly dependent on whether the substrate is hydrophobic or hydrophilic in character, and the energetics of the translocon lateral gate opening in the presence of a peptide substrate is governed by the energetics of the peptide interface with the membrane. Implications of these results for the regulation of Sec-mediated pathways for protein translocation vs. membrane integration are discussed.
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Abstract
Attachment of microorganisms to surfaces is a prerequisite for colonization and biofilm formation. The hyperthermophilic crenarchaeote Sulfolobus solfataricus was able to attach to a variety of surfaces, such as glass, mica, pyrite, and carbon-coated gold grids. Deletion mutant analysis showed that for initial attachment the presence of flagella and pili is essential. Attached cells produced extracellular polysaccharides containing mannose, galactose, and N-acetylglucosamine. Genes possibly involved in the production of the extracellular polysaccharides were identified.
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Different minimal signal peptide lengths recognized by the archaeal prepilin-like peptidases FlaK and PibD. J Bacteriol 2009; 191:6732-40. [PMID: 19717585 DOI: 10.1128/jb.00673-09] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Archaea, the preflagellin peptidase (a type IV prepilin-like peptidase designated FlaK in Methanococcus voltae and Methanococcus maripaludis) is the enzyme that cleaves the N-terminal signal peptide from preflagellins. In methanogens and several other archaeal species, the typical flagellin signal peptide length is 11 to 12 amino acids, while in other archaea preflagellins possess extremely short signal peptides. A systematic approach to address the signal peptide length requirement for preflagellin processing is presented in this study. M. voltae preflagellin FlaB2 proteins with signal peptides 3 to 12 amino acids in length were generated and used as a substrate in an in vitro assay utilizing M. voltae membranes as an enzyme source. Processing by FlaK was observed in FlaB2 proteins containing signal peptides shortened to 5 amino acids; signal peptides 4 or 3 amino acids in length were unprocessed. In the case of Sulfolobus solfataricus, where the preflagellin peptidase PibD has broader substrate specificity, some predicted substrates have predicted signal peptides as short as 3 amino acids. Interestingly, the shorter signal peptides of the various mutant FlaB2 proteins not processed by FlaK were processed by PibD, suggesting that some archaeal preflagellin peptidases are likely adapted toward cleaving shorter signal peptides. The functional complementation of signal peptidase activity by FlaK and PibD in an M. maripaludis DeltaflaK mutant indicated that processing of preflagellins was detected by complementation with either FlaK or PibD, yet only FlaK-complemented cells were flagellated. This suggested that a block in an assembly step subsequent to signal peptide removal occurred in the PibD complementation.
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Kouwen TRHM, van der Ploeg R, Antelmann H, Hecker M, Homuth G, Mäder U, van Dijl JM. Overflow of a hyper-produced secretory protein from the Bacillus Sec pathway into the Tat pathway for protein secretion as revealed by proteogenomics. Proteomics 2009; 9:1018-32. [PMID: 19180538 DOI: 10.1002/pmic.200800580] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Bacteria secrete numerous proteins into their environment for growth and survival under complex and ever-changing conditions. The highly different characteristics of secreted proteins pose major challenges to the cellular protein export machinery and, accordingly, different pathways have evolved. While the main secretion (Sec) pathway transports proteins in an unfolded state, the twin-arginine translocation (Tat) pathway transports folded proteins. To date, these pathways were believed to act in strictly independent ways. Here, we have employed proteogenomics to investigate the secretion mechanism of the esterase LipA of Bacillus subtilis, using a serendipitously obtained hyper-producing strain. While LipA is secreted Sec-dependently under standard conditions, hyper-produced LipA is secreted predominantly Tat-dependently via an unprecedented overflow mechanism. Two previously identified B. subtilis Tat substrates, PhoD and YwbN, require each a distinct Tat translocase for secretion. In contrast, hyper-produced LipA is transported by both Tat translocases of B. subtilis, showing that they have distinct but overlapping specificities. The identified overflow secretion mechanism for LipA focuses interest on the possibility that secretion pathway choice can be determined by environmental and intracellular conditions. This may provide an explanation for the previous observation that many Sec-dependently transported proteins have potential twin-arginine signal peptides for export via the Tat pathway.
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Affiliation(s)
- Thijs R H M Kouwen
- Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands
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Palmieri G, Cannio R, Fiume I, Rossi M, Pocsfalvi G. Outside the unusual cell wall of the hyperthermophilic archaeon Aeropyrum pernix K1. Mol Cell Proteomics 2009; 8:2570-81. [PMID: 19640852 DOI: 10.1074/mcp.m900012-mcp200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In contrast to the extensively studied eukaryal and bacterial protein secretion systems, comparatively less is known about how and which proteins cross the archaeal cell membrane. To identify secreted proteins of the hyperthermophilic archaeon Aeropyrum pernix K1 we used a proteomics approach to analyze the extracellular and cell surface protein fractions. The experimentally obtained data comprising 107 proteins were compared with the in silico predicted secretome. Because of the lack of signal peptide and cellular localization prediction tools specific for archaeal species, programs trained on eukaryotic and/or Gram-positive and Gram-negative bacterial signal peptide data sets were used. PSortB Gram-negative and Gram-positive analysis predicted 21 (1.2% of total ORFs) and 24 (1.4% of total ORFs) secreted proteins, respectively, from the entire A. pernix K1 proteome, 12 of which were experimentally identified in this work. Six additional proteins were predicted to follow non-classical secretion mechanisms using SecP algorithms. According to at least one of the two PSortB predictions, 48 proteins identified in the two fractions possess an unknown localization site. In addition, more than half of the proteins do not contain signal peptides recognized by current prediction programs. This suggests that known mechanisms only partly describe archaeal protein secretion. The most striking characteristic of the secretome was the high number of transport-related proteins identified from the ATP-binding cassette (ABC), tripartite ATP-independent periplasmic, ATPase, small conductance mechanosensitive ion channel (MscS), and dicarboxylate amino acid-cation symporter transporter families. In particular, identification of 21 solute-binding receptors of the ABC superfamily of the 24 predicted in silico confirms that ABC-mediated transport represents the most frequent strategy adopted by A. pernix for solute translocation across the cell membrane.
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Affiliation(s)
- Gianna Palmieri
- Institute of Protein Biochemistry-National Research Council, 80131 Naples, Italy
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Post-translational import of protein into the endoplasmic reticulum of a trypanosome: an in vitro system for discovery of anti-trypanosomal chemical entities. Biochem J 2009; 419:507-17. [PMID: 19196237 DOI: 10.1042/bj20081787] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
HAT (human African trypanosomiasis), caused by the protozoan parasite Trypanosoma brucei, is an emerging disease for which new drugs are needed. Expression of plasma membrane proteins [e.g. VSG (variant surface glycoprotein)] is crucial for the establishment and maintenance of an infection by T. brucei. Transport of a majority of proteins to the plasma membrane involves their translocation into the ER (endoplasmic reticulum). Thus inhibition of protein import into the ER of T. brucei would be a logical target for discovery of lead compounds against trypanosomes. We have developed a TbRM (T. brucei microsome) system that imports VSG_117 post-translationally. Using this system, MAL3-101, equisetin and CJ-21,058 were discovered to be small molecule inhibitors of VSG_117 translocation into the ER. These agents also killed bloodstream T. brucei in vitro; the concentrations at which 50% of parasites were killed (IC50) were 1.5 microM (MAL3-101), 3.3 microM (equisetin) and 7 microM (CJ-21,058). Thus VSG_117 import into TbRMs is a rapid and novel assay to identify 'new chemical entities' (e.g. MAL3-101, equisetin and CJ-21,058) for anti-trypanosome drug development.
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Albers SV, Pohlschröder M. Diversity of archaeal type IV pilin-like structures. Extremophiles 2009; 13:403-10. [PMID: 19347566 DOI: 10.1007/s00792-009-0241-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Accepted: 03/22/2009] [Indexed: 11/26/2022]
Abstract
Bacterial type IV pili perform important functions in such disparate biological processes as surface adhesion, cell-cell interactions, autoaggregation, conjugation, and twitching motility. Unlike bacteria, archaea use a type IV pilus related structure to drive swimming motility. While this unique flagellum is the best-studied example of an archaeal IV pilus-like structure, recent in silico, in vivo and structural analyses have revealed a highly diverse set of archaeal non-flagellar type IV pilus-like structures. Accumulating evidence suggests that these structures play important diverse roles in archaea.
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Affiliation(s)
- Sonja-Verena Albers
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Strasse, 35043, Marburg, Germany.
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42
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Tseng TT, Tyler BM, Setubal JC. Protein secretion systems in bacterial-host associations, and their description in the Gene Ontology. BMC Microbiol 2009; 9 Suppl 1:S2. [PMID: 19278550 PMCID: PMC2654662 DOI: 10.1186/1471-2180-9-s1-s2] [Citation(s) in RCA: 269] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Protein secretion plays a central role in modulating the interactions of bacteria with their environments. This is particularly the case when symbiotic bacteria (whether pathogenic, commensal or mutualistic) are interacting with larger host organisms. In the case of Gram-negative bacteria, secretion requires translocation across the outer as well as the inner membrane, and a diversity of molecular machines have been elaborated for this purpose. A number of secreted proteins are destined to enter the host cell (effectors and toxins), and thus several secretion systems include apparatus to translocate proteins across the plasma membrane of the host also. The Plant-Associated Microbe Gene Ontology (PAMGO) Consortium has been developing standardized terms for describing biological processes and cellular components that play important roles in the interactions of microbes with plant and animal hosts, including the processes of bacterial secretion. Here we survey bacterial secretion systems known to modulate interactions with host organisms and describe Gene Ontology terms useful for describing the components and functions of these systems, and for capturing the similarities among the diverse systems.
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Affiliation(s)
- Tsai-Tien Tseng
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
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Podar M, Anderson I, Makarova KS, Elkins JG, Ivanova N, Wall MA, Lykidis A, Mavromatis K, Sun H, Hudson ME, Chen W, Deciu C, Hutchison D, Eads JR, Anderson A, Fernandes F, Szeto E, Lapidus A, Kyrpides NC, Saier MH, Richardson PM, Rachel R, Huber H, Eisen JA, Koonin EV, Keller M, Stetter KO. A genomic analysis of the archaeal system Ignicoccus hospitalis-Nanoarchaeum equitans. Genome Biol 2008; 9:R158. [PMID: 19000309 PMCID: PMC2614490 DOI: 10.1186/gb-2008-9-11-r158] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 10/21/2008] [Accepted: 11/10/2008] [Indexed: 01/03/2023] Open
Abstract
Sequencing of the complete genome of Ignicoccus hospitalis gives insight into its association with another species of Archaea, Nanoarchaeum equitans. Background The relationship between the hyperthermophiles Ignicoccus hospitalis and Nanoarchaeum equitans is the only known example of a specific association between two species of Archaea. Little is known about the mechanisms that enable this relationship. Results We sequenced the complete genome of I. hospitalis and found it to be the smallest among independent, free-living organisms. A comparative genomic reconstruction suggests that the I. hospitalis lineage has lost most of the genes associated with a heterotrophic metabolism that is characteristic of most of the Crenarchaeota. A streamlined genome is also suggested by a low frequency of paralogs and fragmentation of many operons. However, this process appears to be partially balanced by lateral gene transfer from archaeal and bacterial sources. Conclusions A combination of genomic and cellular features suggests highly efficient adaptation to the low energy yield of sulfur-hydrogen respiration and efficient inorganic carbon and nitrogen assimilation. Evidence of lateral gene exchange between N. equitans and I. hospitalis indicates that the relationship has impacted both genomes. This association is the simplest symbiotic system known to date and a unique model for studying mechanisms of interspecific relationships at the genomic and metabolic levels.
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Affiliation(s)
- Mircea Podar
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN 37831, USA.
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Wang YA, Yu X, Ng SYM, Jarrell KF, Egelman EH. The structure of an archaeal pilus. J Mol Biol 2008; 381:456-66. [PMID: 18602118 DOI: 10.1016/j.jmb.2008.06.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 05/27/2008] [Accepted: 06/05/2008] [Indexed: 11/17/2022]
Abstract
Bacterial pili are involved in a host of activities, including motility, adhesion, transformation, and immune escape. Structural studies of these pili have shown that several distinctly different classes exist, with no common origin. Remarkably, it is now known that the archaeal flagellar filament appears to have a common origin with the bacterial type IV pilus, and assembly in both systems involves hydrophobic N-terminal alpha-helices that form three-stranded coils in the center of these filaments. Recent work has identified further genes in archaea as being similar to bacterial type IV pilins, but the function or structures formed by such gene products was unknown. Using electron cryo-microscopy, we show that an archaeal pilus from Methanococcus maripaludis has a structure entirely different from that of any of the known bacterial pili. Two subunit packing arrangements were identified: one has rings of four subunits spaced by approximately 44 A and the other has a one-start helical symmetry with approximately 2.6 subunits per turn of a approximately 30 A pitch helix. Remarkably, these schemes appear to coexist within the same filaments. For the segments composed of rings, the twist between adjacent rings is quite variable, while for the segments having a one-start helix there is a large variability in both the axial rise and the twist per subunit. Since this pilus appears to be assembled from a type IV pilin-like protein with a hydrophobic N-terminal helix, it provides yet another example of how different quaternary structures can be formed from similar building blocks. This result has many implications for understanding the evolutionary divergence of bacteria and archaea.
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Affiliation(s)
- Ying A Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia, Box 800733, Charlottesville, VA 22908-0733, USA
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Jankovic D, Collett MA, Lubbers MW, Rakonjac J. Direct selection and phage display of a Gram-positive secretome. Genome Biol 2008; 8:R266. [PMID: 18078523 PMCID: PMC2246268 DOI: 10.1186/gb-2007-8-12-r266] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2007] [Revised: 11/01/2007] [Accepted: 12/13/2007] [Indexed: 12/23/2022] Open
Abstract
A phage display system for direct selection, identification, expression and purification of bacterial secretome proteins has been developed. Surface, secreted and transmembrane protein-encoding open reading frames, collectively the secretome, can be identified in bacterial genome sequences using bioinformatics. However, functional analysis of translated secretomes is possible only if many secretome proteins are expressed and purified individually. We have now developed and applied a phage display system for direct selection, identification, expression and purification of bacterial secretome proteins.
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Affiliation(s)
- Dragana Jankovic
- Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand.
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Sec- and Tat-mediated protein secretion across the bacterial cytoplasmic membrane--distinct translocases and mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1778:1735-56. [PMID: 17935691 DOI: 10.1016/j.bbamem.2007.07.015] [Citation(s) in RCA: 340] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 07/23/2007] [Accepted: 07/24/2007] [Indexed: 11/20/2022]
Abstract
In bacteria, two major pathways exist to secrete proteins across the cytoplasmic membrane. The general Secretion route, termed Sec-pathway, catalyzes the transmembrane translocation of proteins in their unfolded conformation, whereupon they fold into their native structure at the trans-side of the membrane. The Twin-arginine translocation pathway, termed Tat-pathway, catalyses the translocation of secretory proteins in their folded state. Although the targeting signals that direct secretory proteins to these pathways show a high degree of similarity, the translocation mechanisms and translocases involved are vastly different.
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Phylogenomics of the archaeal flagellum: rare horizontal gene transfer in a unique motility structure. BMC Evol Biol 2007; 7:106. [PMID: 17605801 PMCID: PMC1914349 DOI: 10.1186/1471-2148-7-106] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Accepted: 07/02/2007] [Indexed: 11/10/2022] Open
Abstract
Background As bacteria, motile archaeal species swim by means of rotating flagellum structures driven by a proton gradient force. Interestingly, experimental data have shown that the archaeal flagellum is non-homologous to the bacterial flagellum either in terms of overall structure, components and assembly. The growing number of complete archaeal genomes now permits to investigate the evolution of this unique motility system. Results We report here an exhaustive phylogenomic analysis of the components of the archaeal flagellum. In all complete archaeal genomes, the genes coding for flagellum components are co-localized in one or two well-conserved genomic clusters showing two different types of organizations. Despite their small size, these genes harbor a good phylogenetic signal that allows reconstruction of their evolutionary histories. These support a history of mainly vertical inheritance for the components of this unique motility system, and an interesting possible ancient horizontal gene transfer event (HGT) of a whole flagellum-coding gene cluster between Euryarchaeota and Crenarchaeota. Conclusion Our study is one of the few exhaustive phylogenomics analyses of a non-informational cell machinery from the third domain of life. We propose an evolutionary scenario for the evolution of the components of the archaeal flagellum. Moreover, we show that the components of the archaeal flagellar system have not been frequently transferred among archaeal species, indicating that gene fixation following HGT can also be rare for genes encoding components of large macromolecular complexes with a structural role.
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Zolghadr B, Weber S, Szabó Z, Driessen AJM, Albers SV. Identification of a system required for the functional surface localization of sugar binding proteins with class III signal peptides in Sulfolobus solfataricus. Mol Microbiol 2007; 64:795-806. [PMID: 17462024 DOI: 10.1111/j.1365-2958.2007.05697.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The hyperthermophilic archaeon Sulfolobus solfataricus contains an unusual large number of sugar binding proteins that are synthesized as precursors with a class III signal peptide. Such signal peptides are commonly used to direct archaeal flagellin subunits or bacterial (pseudo)pilins into extracellular macromolecular surface appendages. Likewise, S. solfataricus binding proteins have been suggested to assemble in higher ordered surface structures as well, tentatively termed the bindosome. Here we show that S. solfataricus contains a specific system that is needed for the functional surface localization of sugar binding proteins. This system, encoded by the bas (bindosome assembly system) operon, is composed of five proteins: basABC, three homologues of so-called bacterial (pseudo)pilins; BasE, a cytoplasmic ATPase; and BasF, an integral membrane protein. Deletion of either the three (pseudo)pilin genes or the basEF genes resulted in a severe defect of the cells to grow on substrates which are transported by sugar binding proteins containing class III signal peptides, while growth on glucose and maltose was restored when the corresponding genes were reintroduced in these cells. Concomitantly, DeltabasABC and DeltabasEF cells were severely impaired in glucose uptake even though the sugar binding proteins were normally secreted across the cytoplasmic membrane. These data underline the hypothesis that the bas operon is involved in the functional localization of sugar binding proteins at the cell surface of S. solfataricus. In contrast to surface structure assembly systems of Gram-negative bacteria, the bas operon seems to resemble an ancestral simplified form of these machineries.
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Affiliation(s)
- Behnam Zolghadr
- Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute and the Materials Science Centre Plus, University of Groningen, Kerklaan 30, 9751 NN HAREN, The Netherlands
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Szabó Z, Sani M, Groeneveld M, Zolghadr B, Schelert J, Albers SV, Blum P, Boekema EJ, Driessen AJM. Flagellar motility and structure in the hyperthermoacidophilic archaeon Sulfolobus solfataricus. J Bacteriol 2007; 189:4305-9. [PMID: 17416662 PMCID: PMC1913377 DOI: 10.1128/jb.00042-07] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Flagellation in archaea is widespread and is involved in swimming motility. Here, we demonstrate that the structural flagellin gene from the crenarchaeaon Sulfolobus solfataricus is highly expressed in stationary-phase-grown cells and under unfavorable nutritional conditions. A mutant in a flagellar auxiliary gene, flaJ, was found to be nonmotile. Electron microscopic imaging of the flagellum indicates that the filaments are composed of right-handed helices.
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Affiliation(s)
- Zalán Szabó
- Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands
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