scholarly journals A comprehensive history of motility and Archaellation in Archaea

FEMS Microbes ◽  
2021 ◽  
Author(s):  
Ken F Jarrell ◽  
Sonja-Verena Albers ◽  
J Nuno de Sousa Machado
Keyword(s):  
Posttranslational Modifications ◽  
State Of The Art ◽  
Halophilic Archaea ◽  
Biotechnological Potential ◽  
Type Iv ◽  
Domains Of Life ◽  
History Of ◽  
Archaeal Flagellum ◽  
Comprehensive History ◽  
Made In

Abstract Each of the three Domains of life, Eukarya, Bacteria and Archaea, have swimming structures that were all originally called flagella, despite the fact that none were evolutionarily related to either of the other two. Surprisingly, this was true even in the two prokaryotic Domains of Bacteria and Archaea. Beginning in the 1980s, evidence gradually accumulated that convincingly demonstrated that the motility organelle in Archaea was unrelated to that found in Bacteria, but surprisingly shared significant similarities to type IV pili. This information culminated in the proposal, in 2012, that the ‘archaeal flagellum’ be assigned a new name, the archaellum. In this review, we provide a historical overview on archaella and motility research in Archaea, beginning with the first simple observations of motile extreme halophilic archaea a century ago up to state-of-the-art cryo-tomography of the archaellum motor complex and filament observed today. In addition to structural and biochemical data which revealed the archaellum to be a type IV pilus-like structure repurposed as a rotating nanomachine (Beeby et al. 2020), we also review the initial discoveries and subsequent advances using a wide variety of approaches to reveal: complex regulatory events that lead to the assembly of the archaellum filaments (archaellation); the roles of the various archaellum proteins; key posttranslational modifications of the archaellum structural subunits; evolutionary relationships; functions of archaella other than motility and the biotechnological potential of this fascinating structure. The progress made in understanding the structure and assembly of the archaellum is highlighted by comparing early models to what is known today.

Assembly and function of the archaeal flagellum

2011 ◽  
Vol 39 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Abhrajyoti Ghosh ◽  
Sonja-Verena Albers
Keyword(s):  
Evolutionary Relationship ◽  
Type Iv Pili ◽  
Assembly Systems ◽  
Sequence Information ◽  
Type Iv ◽  
Core Proteins ◽  
Domains Of Life ◽  
Interaction Map ◽  
Archaeal Flagellum ◽  
Bacterial Type

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.

scholarly journals Diversification of the type IV filament super-family into machines for adhesion, secretion, DNA transformation and motility

2019 ◽  
Author(s):  
Rémi Denise ◽  
Sophie S Abby ◽  
Eduardo PC Rocha
Keyword(s):  
Natural History ◽  
Protein Secretion ◽  
Molecular Mechanisms ◽  
Genetic Regulation ◽  
Dna Transformation ◽  
Secretion Systems ◽  
Molecular Systems ◽  
Type Iv ◽  
Domains Of Life ◽  
History Of

AbstractProcesses of molecular innovation require tinkering and co-option of existing genes. How this occurs in terms of molecular evolution at long evolutionary scales remains poorly understood. Here, we analyse the natural history of a vast group of membrane-associated molecular systems in Bacteria and Archaea – type IV filament super-family (TFF-SF) – that diversified in systems involved in flagellar or twitching motility, adhesion, protein secretion, and DNA natural transformation. We identified such systems in all phyla of the two domains of life, and their phylogeny suggests that they may have been present in the last universal common ancestor. From there, two lineages, a Bacterial and an Archaeal, diversified by multiple gene duplications of the ATPases, gene fission of the integral membrane platform, and accretion of novel components. Surprisingly, we find that the Tad systems originated from the inter-kingdom transfer from Archaea to Bacteria of a system resembling the Epd pilus. The phylogeny and content of ancestral systems suggest that initial bacterial pili were engaged in cell motility and/or DNA transformation. In contrast, specialized protein secretion systems arose much later, and several independent times, in natural history. All these processes of functional diversification were accompanied by genetic rearrangements with implications for genetic regulation and horizontal gene transfer: systems encoded in fewer loci were more frequently exchanged between taxa. Overall, the evolutionary history of the TFF-SF by itself provides an impressive catalogue of the variety of molecular mechanisms involved in the origins of novel functions by tinkering and co-option of cellular machineries.

A history of botanical collections in the Luangwa Valley, Zambia

1998 ◽  
Vol 25 (2) ◽  
pp. 283-291
Author(s):  
P.S.M. PHIRI ◽  
D.M. MOORE
Keyword(s):  
Eighteenth Century ◽  
Environmental Impact ◽  
Impact Assessment ◽  
Vascular Plants ◽  
Central Africa ◽  
Peak Activity ◽  
Historical Account ◽  
History Of ◽  
The 1960S ◽  
Made In

Central Africa remained botanically unknown to the outside world up to the end of the eighteenth century. This paper provides a historical account of plant explorations in the Luangwa Valley. The first plant specimens were collected in 1897 and the last serious botanical explorations were made in 1993. During this period there have been 58 plant collectors in the Luangwa Valley with peak activity recorded in the 1960s. In 1989 1,348 species of vascular plants were described in the Luangwa Valley. More botanical collecting is needed with a view to finding new plant taxa, and also to provide a satisfactory basis for applied disciplines such as ecology, phytogeography, conservation and environmental impact assessment.

Chasing Angels: The Sweet Wine Angelica

2008 ◽  
Vol 8 (3) ◽  
pp. 74-78
Author(s):  
hank shaw
Keyword(s):  
The State ◽  
The Real ◽  
Mission Period ◽  
History Of ◽  
Uncertain Future ◽  
Sweet Wine ◽  
Made In

Portugal has port, Spain has sherry, Sicily has Marsala –– and California has angelica. Angelica is California's original wine: The intensely sweet, fortified dessert cordial has been made in the state for more than two centuries –– primarily made from Mission grapes, first brought to California by the Spanish friars. Angelica was once drunk in vast quantities, but now fewer than a dozen vintners make angelica today. These holdouts from an earlier age are each following a personal quest for the real. For unlike port and sherry, which have strict rules about their production, angelica never gelled into something so distinct that connoisseurs can say, ““This is angelica. This is not.”” This piece looks at the history of the drink, its foggy origins in the Mission period and on through angelica's heyday and down to its degeneration into a staple of the back-alley wino set. Several current vintners are profiled, and they suggest an uncertain future for this cordial.

Not as It Is Written

2020 ◽  
Vol 42 (2) ◽  
pp. 78-100
Author(s):  
Benjamin Houston
Keyword(s):  
African American ◽  
Civil Rights ◽  
Oral History ◽  
Civil Rights Movement ◽  
International Exhibition ◽  
Black Experience ◽  
American Perspective ◽  
History Of ◽  
Black Life ◽  
Made In

This article discusses an international exhibition that detailed the recent history of African Americans in Pittsburgh. Methodologically, the exhibition paired oral history excerpts with selected historic photographs to evoke a sense of Black life during the twentieth century. Thematically, showcasing the Black experience in Pittsburgh provided a chance to provoke among a wider public more nuanced understandings of the civil rights movement, an era particularly prone to problematic and superficial misreadings, but also to interject an African American perspective into the scholarship on deindustrializing cities, a literature which treats racism mostly in white-centric terms. This essay focuses on the choices made in reconciling these thematic and methodological dimensions when designing this exhibition.

RISHTAN SCHOOL OF CERAMICS

2019 ◽  
Vol 16 (2) ◽  
pp. 73-77
Author(s):  
Akmal Marozikov ◽  
Keyword(s):  
Central Asia ◽  
Building Materials ◽  
Works Of Art ◽  
The World ◽  
Ferghana Valley ◽  
History Of ◽  
Made In ◽  
National Style

Ceramics is an area that has a long history of making clay bowls, bowls, plates,pitchers, bowls, bowls, bowls, pots, pans, toys, building materials and much more.Pottery developed in Central Asia in the XII-XIII centuries. Rishtan school, one of the oldest cities in the Ferghana Valley, is one of the largest centers of glazed ceramics inCentral Asia. Rishtan ceramics and miniatures are widely recognized among the peoples of the world and are considered one of the oldest cities in the Ferghana Valley. The article discusses the popularity of Rishtan masters, their products made in the national style,and works of art unique to any region

Biological Production of (S)-acetoin: A State-of-the-Art Review

2019 ◽  
Vol 19 (25) ◽  
pp. 2348-2356 ◽  
Author(s):  
Neng-Zhong Xie ◽  
Jian-Xiu Li ◽  
Ri-Bo Huang
Keyword(s):  
Side Effects ◽  
Chemical Synthesis ◽  
State Of The Art ◽  
Optically Active ◽  
Considerable Progress ◽  
Future Prospects ◽  
Chiral Compound ◽  
Biological Production ◽  
Acetoin Production ◽  
Made In

Acetoin is an important four-carbon compound that has many applications in foods, chemical synthesis, cosmetics, cigarettes, soaps, and detergents. Its stereoisomer (S)-acetoin, a high-value chiral compound, can also be used to synthesize optically active drugs, which could enhance targeting properties and reduce side effects. Recently, considerable progress has been made in the development of biotechnological routes for (S)-acetoin production. In this review, various strategies for biological (S)- acetoin production are summarized, and their constraints and possible solutions are described. Furthermore, future prospects of biological production of (S)-acetoin are discussed.

Biological NMR Spectroscopy

1997 ◽  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
State Of The Art ◽  
Critical Assessment ◽  
Resonance Spectroscopy ◽  
History Of ◽  
Structure Of Proteins

This book presents a critical assessment of progress on the use of nuclear magnetic resonance spectroscopy to determine the structure of proteins, including brief reviews of the history of the field along with coverage of current clinical and in vivo applications. The book, in honor of Oleg Jardetsky, one of the pioneers of the field, is edited by two of the most highly respected investigators using NMR, and features contributions by most of the leading workers in the field. It will be valued as a landmark publication that presents the state-of-the-art perspectives regarding one of today's most important technologies.

Computers in Geology - 25 Years of Progress

1994 ◽  
Keyword(s):  
Computer Modeling ◽  
Quantitative Methods ◽  
State Of The Art ◽  
International Association ◽  
Mathematical Geology ◽  
25Th Anniversary ◽  
The Earth ◽  
Wide Range ◽  
History Of ◽  
Mapping Techniques

This volume vividly demonstrates the importance and increasing breadth of quantitative methods in the earth sciences. With contributions from an international cast of leading practitioners, chapters cover a wide range of state-of-the-art methods and applications, including computer modeling and mapping techniques. Many chapters also contain reviews and extensive bibliographies which serve to make this an invaluable introduction to the entire field. In addition to its detailed presentations, the book includes chapters on the history of geomathematics and on R.G.V. Eigen, the "father" of mathematical geology. Written to commemorate the 25th anniversary of the International Association for Mathematical Geology, the book will be sought after by both practitioners and researchers in all branches of geology.

The Art of Love Poetry

2018 ◽  
Author(s):  
Erik Gray
Keyword(s):  
Popular Culture ◽  
Cultural History ◽  
Literary Tradition ◽  
Love Poetry ◽  
Erotic Love ◽  
Wide Range ◽  
History Of ◽  
And Function ◽  
Meaning And Function ◽  
Comprehensive History

Love begets poetry; poetry begets love. These two propositions have seemed evident to thinkers and poets across the Western literary tradition. Plato writes that “anyone that love touches instantly becomes a poet.” And even today, when poetry has largely disappeared from the mainstream of popular culture, it retains its romantic associations. But why should this be so—what are the connections between poetry and erotic love that lead us to associate them so strongly with one another? An examination of different theories of both love and poetry across the centuries reveals that the connection between them is not merely an accident of cultural history—the result of our having grown up hearing, or hearing about, love poetry—but something more intrinsic. Even as definitions of them have changed, the two phenomena have consistently been described in parallel terms. Love is characterized by paradox. Above all, it is both necessarily public, because interpersonal, and intensely private; hence it both requires expression and resists it. In poetry, especially lyric poetry, which features its own characteristic paradoxes and silences, love finds a natural outlet. This study considers both the theories and the love poems themselves, bringing together a wide range of examples from different eras in order to examine the major structures that love and poetry share. It does not aim to be a comprehensive history of Western love poetry, but an investigation into the meaning and function of recurrent tropes, forms, and images employed by poets to express and describe erotic love.

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