scholarly journals The structural biology of the shelterin complex

2019 ◽  
Vol 400 (4) ◽  
pp. 457-466 ◽  
Author(s):  
Yong Chen
Keyword(s):  
Structural Biology ◽  
Structural Features ◽  
Chromosome Stability ◽  
Structural Studies ◽  
Telomeric Dna ◽  
Structural Domains ◽  
The Past ◽  
Shelterin Complex ◽  
Telomere Homeostasis

Abstract The shelterin complex protects telomeric DNA and plays critical roles in maintaining chromosome stability. The structures and functions of the shelterin complex have been extensively explored in the past decades. This review summarizes the current progress on structural studies of shelterin complexes from different species. It focuses on the structural features and assembly of common structural domains, highlighting the evolutionary plasticity and conserved roles of shelterin proteins in telomere homeostasis and protection.

Active Fault Systems in the inner North West Apennines: an updated view

2021 ◽  
Author(s):  
Giancarlo Molli ◽  
Rick Bennett ◽  
Jacques Malavieille ◽  
Enrico Serpelloni ◽  
Fabrizio Storti ◽  
...  
Keyword(s):  
Active Fault ◽  
Central Italy ◽  
Structural Features ◽  
Structural Studies ◽  
Data Set ◽  
Structural Domains ◽  
North West ◽  
Fault Systems ◽  
Internal Fault ◽  
Fault Characterization

<p>As part of an ongoing project of mapping, structural studies and fault characterization we present an updated tectonic scheme and data set for the active fault systems that shaped the inner portion of the Apennines north of the Arno river. Geomorphology, stratigraphy of Plio-Quaternary sediments, GPS data, historical and instrumental seismicity have been reviewed and combined with structural studies to define the neotectonic history of the investigated region. Within the studied area, first-order physiographic and structural features allow to define different structural domains related to a set of ranges with a dominant NW-SE direction separated by intramontane or continental/marine morphotectonic depressions of the Lunigiana, Garfagnana, Lucca-Mt.Albano, La Spezia-Carrara and the off-shore Viareggio basin. The main boundary faults and internal fault segments of the different structural domains were described while the Plio-Quaternary sedimentary records has been used to constrain their long to short term deformation and rates, with the aim to improve current Italian catalogues - DISS (INGV) and Ithaca (ISPRA) - with some utilities for the seismic microzonation local projects. Moreover, our work aims to draw the attention of the scientific community to the seismotectonics of a region in which the seismic hazard is largely considered medium to low despite the occurrence, one century ago, of one of the most destructive earthquakes that have struck the Italian peninsula, the 1920 Fivizzano EQ, with an estimated Mw 6.5 similar to the main shock of the 2016 Central Italy seismic sequence.</p><p> </p>

Chemical insights from structural studies of enzymes

2004 ◽  
Vol 32 (5) ◽  
pp. 647-654 ◽  
Author(s):  
J.H. Naismith
Keyword(s):  
Structural Analysis ◽  
Molecular Biology ◽  
Structural Biology ◽  
Structural Information ◽  
Integral Membrane Protein ◽  
Structural Studies ◽  
Rapid Progress ◽  
Chemical Mechanisms ◽  
The Past ◽  
Processing Pathways

The rapid progress in structural and molecular biology over the past fifteen years has allowed chemists to access the structures of enzymes, of their complexes and of mutants. This wealth of structural information has led to a surge in the interest in enzymes as elegant chemical catalysts. Enzymology is a distinguished field and has been making vital contributions to medicine and basic science long before structural biology. This review for the Colworth Medal Lecture discusses work from the author's laboratory. This work has been carried out in collaboration with many other laboratories. The work has mapped out the chemical mechanisms and structures of interesting novel enzymes. The review tries to highlight the interesting chemical aspects of the mechanisms involved and how structural analysis has provided a detailed insight. The review focuses on carbohydrate-processing pathways in bacteria, and includes some recent data on an integral membrane protein.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

scholarly journals Sphingolipids of Asteroidea and Holothuroidea: Structures and Biological Activities

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 330
Author(s):  
Timofey V. Malyarenko ◽  
Alla A. Kicha ◽  
Valentin A. Stonik ◽  
Natalia V. Ivanchina
Keyword(s):  
Marine Invertebrates ◽  
Biological Activities ◽  
Complete Information ◽  
Structural Features ◽  
Marine Organisms ◽  
Structural Components ◽  
Chemical Structures ◽  
The Past ◽  
Complex Lipids ◽  
Complex Sphingolipids

Sphingolipids are complex lipids widespread in nature as structural components of biomembranes. Commonly, the sphingolipids of marine organisms differ from those of terrestrial animals and plants. The gangliosides are the most complex sphingolipids characteristic of vertebrates that have been found in only the Echinodermata (echinoderms) phylum of invertebrates. Sphingolipids of the representatives of the Asteroidea and Holothuroidea classes are the most studied among all echinoderms. In this review, we have summarized the data on sphingolipids of these two classes of marine invertebrates over the past two decades. Recently established structures, properties, and peculiarities of biogenesis of ceramides, cerebrosides, and gangliosides from starfishes and holothurians are discussed. The purpose of this review is to provide the most complete information on the chemical structures, structural features, and biological activities of sphingolipids of the Asteroidea and Holothuroidea classes.

Neighborhoods and Intimate Partner Violence: A Decade in Review

2021 ◽  
pp. 155708512098763
Author(s):  
Emily M. Wright ◽  
Gillian M. Pinchevsky ◽  
Min Xie
Keyword(s):  
Intimate Partner Violence ◽  
Partner Violence ◽  
Structural Features ◽  
Intimate Partner ◽  
Neighborhood Context ◽  
Policy Implications ◽  
Economic Disadvantage ◽  
The Past ◽  
Research Findings ◽  
And Gender

We consider the broad developments that have occurred over the past decade regarding our knowledge of how neighborhood context impacts intimate partner violence (IPV). Research has broadened the concept of “context” beyond structural features such as economic disadvantage, and extended into relationships among residents, collective “action” behaviors among residents, cultural and gender norms. Additionally, scholars have considered how the built environment might foster (or regulate) IPV. We now know more about the direct, indirect, and moderating ways that communities impact IPV. We encourage additional focus on the policy implications of the research findings.

scholarly journals Single-particle cryo-EM—How did it get here and where will it go

Science ◽  
2018 ◽  
Vol 361 (6405) ◽  
pp. 876-880 ◽  
Author(s):  
Yifan Cheng
Keyword(s):  
Electron Microscopy ◽  
Structural Biology ◽  
Single Particle ◽  
Electron Crystallography ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Technological Advances ◽  
The Future ◽  
Electron Cryotomography

Cryo–electron microscopy, or simply cryo-EM, refers mainly to three very different yet closely related techniques: electron crystallography, single-particle cryo-EM, and electron cryotomography. In the past few years, single-particle cryo-EM in particular has triggered a revolution in structural biology and has become a newly dominant discipline. This Review examines the fascinating story of its start and evolution over the past 40-plus years, delves into how and why the recent technological advances have been so groundbreaking, and briefly considers where the technique may be headed in the future.

The Glossary

2020 ◽  
pp. 8-35
Author(s):  
Drew Massey
Keyword(s):  
Structural Features ◽  
Source Material ◽  
The Past

This chapter considers Adès’s compositional priorities by exploring his works which respond to complete, pre-existing musical pieces. I refer to these efforts collectively as Adès’s glossary. These glosses refract an existing piece through the lens of his own aesthetic, and also constitute a kind of commentary on practices through which composers have historically recruited music of the past into their work. Moreover, Adès’s engagements with composers ranging from Dowland to Nancarrow can be grouped according to a few overarching goals. Some of his glosses seek to comment or clarify on the harmonic or structural features of a piece; others focus on questions of performativity. In the case of his reconfiguration of his own music, Adès engages in a process of intensification of the source material, resulting in self-borrowings which distill the sometimes uncanny—or even disturbing—qualities present in the originals.

scholarly journals Intra-locked G-quadruplex structures formed by irregular DNA G-rich motifs

2020 ◽  
Vol 48 (6) ◽  
pp. 3315-3327 ◽  
Author(s):  
Arijit Maity ◽  
Fernaldo Richtia Winnerdy ◽  
Weili Denyse Chang ◽  
Gang Chen ◽  
Anh Tuân Phan
Keyword(s):  
Human Genome ◽  
Dna Sequences ◽  
Structural Features ◽  
Nmr Structure ◽  
Solution Nmr ◽  
Structural Studies ◽  
High Propensity ◽  
G Quadruplex ◽  
High Prevalence

Abstract G-rich DNA sequences with tracts of three or more continuous guanines (G≥3) are known to have high propensity to adopt stable G-quadruplex (G4) structures. Bioinformatic analyses suggest high prevalence of G-rich sequences with short G-tracts (G≤2) in the human genome. However, due to limited structural studies, the folding principles of such sequences remain largely unexplored and hence poorly understood. Here, we present the solution NMR structure of a sequence named AT26 consisting of irregularly spaced G2 tracts and two isolated single guanines. The structure is a four-layered G4 featuring two bi-layered blocks, locked between themselves in an unprecedented fashion making it a stable scaffold. In addition to edgewise and propeller-type loops, AT26 also harbors two V-shaped loops: a 2-nt V-shaped loop spanning two G-tetrad layers and a 0-nt V-shaped loop spanning three G-tetrad layers, which are named as VS- and VR-loop respectively, based on their distinct structural features. The intra-lock motif can be a basis for extending the G-tetrad core and a very stable intra-locked G4 can be formed by a sequence with G-tracts of various lengths including several G2 tracts. Findings from this study will aid in understanding the folding of G4 topologies from sequences containing irregularly spaced multiple short G-tracts.

scholarly journals Terpenoids and Sterols from Some Japanese Mushrooms

2014 ◽  
Vol 9 (3) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Yasunori Yaoita ◽  
Masao Kikuchi ◽  
Koichi Machida
Keyword(s):  
Lentinula Edodes ◽  
Chemical Constituents ◽  
Structural Features ◽  
Tricholoma Matsutake ◽  
Pholiota Nameko ◽  
The Past ◽  
Polyporus Umbellatus ◽  
Hericium Erinaceum ◽  
New Compounds ◽  
Hypsizigus Marmoreus

Over the past twenty years, our research group has been studying the chemical constituents of mushrooms. From nineteen species, namely, Amanita virgineoides Bas (Amanitaceae), Daedaleopsis tricolor (Bull.: Fr.) Bond. et Sing. (Polyporaceae), Grifola frondosa (Fr.) S. F. Gray (Polyporaceae), Hericium erinaceum (Bull.: Fr.) Pers. (Hericiaceae), Hypsizigus marmoreus (Peck) Bigelow (Tricholomataceae), Lactarius piperatus (Scop.: Fr.) S. F. Gray (Russulaceae), Lentinula edodes (Berk.) Sing. (Pleurotaceae), Lyophyllyum connatum (Schum.: Fr.) Sing. (Tricholomataceae), Naematoloma sublateritium (Fr.) Karst. (Strophariaceae), Ompharia lapidescens Schroeter (Polyporaceae), Panellus serotinus (Pers.: Fr.) Kuhn. (Tricholomataceae), Pholiota nameko (T. Ito) S. Ito et Imai in Imai (Strophariaceae), Pleurotus eringii (DC.: Fr.) Quel. (Pleurotaceae), Polyporus umbellatus Fries (Polyporaceae), Russula delica Fr. (Russulaceae), Russula sanguinea (Bull.) Fr. (Russulaceae), Sarcodon aspratus (Berk.) S. Ito (Thelephoraceae), Tricholoma matsutake (S. Ito et Imai) Sing. (Tricholomataceae), and Tricholoma portentosum (Fr.) Quel. (Tricholomataceae), we isolated eight new sesquiterpenoids, six new meroterpenoids, three new triterpenoids, and twenty eight new sterols. In this review, structural features of these new compounds are discussed.

scholarly journals Preventing Bio-Bloopers and XFEL Follies: Best Practices from your Friendly Instrument Staff

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 251 ◽  
Author(s):  
Christopher Kupitz ◽  
Raymond G. Sierra
Keyword(s):  
Best Practices ◽  
Structural Biology ◽  
High Speed ◽  
X Ray ◽  
Experimental Planning ◽  
The Past ◽  
Delivery Technique ◽  
Scientific Goal ◽  
Paradigm Shifting ◽  
Serial Femtosecond Crystallography

Serial Femtosecond Crystallography (SFX) at X-ray Free electron Lasers (XFELs) is a relatively new field promising to deliver unparalleled spatial and temporal resolution on biological systems and there dynamics. Over the past decade, though, there have been a handful of results that have truly delivered on these promises. Why? SFX has many paradigm shifting techniques not seen in typical structural biology arenas, such as creating a concentrated slurry of microcrystals rather than a handful of loopable prisms worthy of a catalog photo. Then taking that slurry and high speed jetting them towards the vacuum or helium interation region to destroy less than 1% of your sample and waste the other 99. The literature is full of techniques and methods promising to cure what ails your experiment, yet as an instrument scientist will tell you –and a first author might admit after a few drinks at the conference happy hour—is that there are a lot more failures than the success we published, results may vary. We will walk through a best practices on how to prepare your sample and chose a sample delivery technique that will amerliorate your studies rather than undermine your hardwork and hopefully lead to better experimental planning and execution, inching you closer to that scientific goal and that call from Stockholm. This will be written in a more editorialized fashion and is meant to give the reader an idea of what to try or how they should be thinking. Welcome to SFX, now what?

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