scholarly journals Emergence of a recurrent insertion in the N-terminal domain of the SARS-CoV-2 spike glycoprotein

2022 ◽  
pp. 198674
Author(s):  
Marco Gerdol ◽  
Klevia Dishnica ◽  
Alejandro Giorgetti
Keyword(s):  
Spike Glycoprotein ◽  
Terminal Domain

scholarly journals Structural definition of a neutralization epitope on the N-terminal domain of MERS-CoV spike glycoprotein

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Haixia Zhou ◽  
Yingzhu Chen ◽  
Shuyuan Zhang ◽  
Peihua Niu ◽  
Kun Qin ◽  
...  
Keyword(s):  
Spike Glycoprotein ◽  
Neutralization Epitope ◽  
Terminal Domain ◽  
Definition Of ◽  
Structural Definition

scholarly journals Emergence of a recurrent insertion in the N-terminal domain of the SARS-CoV-2 spike glycoprotein

2021 ◽  
Author(s):  
Marco Gerdol
Keyword(s):  
Neutralizing Antibodies ◽  
Immune Escape ◽  
Progressive Increase ◽  
Spike Glycoprotein ◽  
Synonymous Mutations ◽  
Terminal Domain ◽  
Surveillance Programs ◽  
Key Sites ◽  
Partial Overlap ◽  
Antibody Epitopes

Tracking the evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through genomic surveillance programs is undoubtedly one of the key priorities in the current pandemic situation. Although the genome of SARS-CoV-2 acquires mutations at a slower rate compared with other RNA viruses, evolutionary pressures derived from the widespread circulation of SARS-CoV-2 in the human population have progressively favored the global emergence though natural selection of several variants of concern that carry multiple non-synonymous mutations in the spike glycoprotein. Such mutations are often placed in key sites within major antibody epitopes and may therefore confer resistance to neutralizing antibodies, leading to partial immune escape, or otherwise compensate minor infectivity deficits associated with other mutations. As previously shown by other authors, several emerging variants carry recurrent deletion regions (RDRs) that display a partial overlap with antibody epitopes located in the spike N-terminal domain. Comparatively, very little attention has been directed towards spike insertion mutations, which often go unnoticed due to the use of insertion-unaware bioinformatics analysis pipelines. This manuscript describe a single recurrent insertion region (RIR1) in the N-terminal domain of SARS-CoV-2 spike protein, characterized by the independent acquisition of 3-4 additional codons between Arg214 and Asp215 in different viral lineages. Even though RIR1 is unlikely to confer antibody escape, its progressive increase in frequency and its association with two distinct emerging lineages (A.2.5 and B.1.214.2) warrant further investigation concerning its effects on spike structure and viral infectivity.

scholarly journals Real Concerns over COVID-19 Variants of Concern

2021 ◽  
Author(s):  
Hatem ◽  
Rashika El Rii
Keyword(s):  
United States ◽  
Severe Acute Respiratory Syndrome ◽  
Receptor Binding ◽  
Immune Evasion ◽  
The United States ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Spike Glycoprotein ◽  
Terminal Domain ◽  
Corona Virus

Severe acute respiratory syndrome corona virus (SARS-CoV)-2 obtained from patients infected despite being fully vaccinated with either BNT162b2 (Pfizer/BioNTech), mRNA-1273 (Moderna), or JNJ-78436735 (Janssen) showed increased mutations rates in the N-terminal domain (NTD) and receptor-binding domain (RBD) of the spike glycoprotein when compared with virus from unvaccinated controls (1). These changes are associated with immune evasion and diagnostic failures, prominent characteristics of variants of concern (2). Variants of concern (VOC) appeared to be overrepresented in numerous breakthrough infections of fully vaccinated people in the United States and (1, 3-6), and Israel (7). These findings confirm concerns about the relation of SARS-CoV-2 variants with vaccine breakthrough, and urged us to attempt clarifying the likely link between vaccination with the currently used vaccines and VOC emergence.

Structure of clathrin cages and coats in ice

1986 ◽  
Vol 44 ◽  
pp. 94-97
Author(s):  
G.P.A. Vigers ◽  
R.A. Crowther ◽  
B.M.F. Pearse
Keyword(s):  
Electron Microscopy ◽  
Heavy Chain ◽  
Outer Part ◽  
Coated Vesicles ◽  
Eukaryotic Cells ◽  
Coat Proteins ◽  
Terminal Domain ◽  
Clathrin Heavy Chain ◽  
Membrane Components

Clathrin forms the polyhedral cage of coated vesicles, which mediate the transfer of selected membrane components within eukaryotic cells. Clathrin cages and coated vesicles have been extensively studied by electron microscopy of negatively stained preparations and shadowed specimens. From these studies the gross morphology of the outer part of the polyhedral coat has been established and some features of the packing of clathrin trimers into the coat have also been described. However these previous studies have not revealed any internal details about the position of the terminal domain of the clathrin heavy chain, the location of the 100kd-50kd accessory coat proteins or the interactions of the coat with the enclosed membrane.

Crystal structures of Magnaporthe oryzae trehalose-6-phosphate synthase (MoTps1) suggest a model for catalytic process of Tps1

2019 ◽  
Vol 476 (21) ◽  
pp. 3227-3240 ◽  
Author(s):  
Shanshan Wang ◽  
Yanxiang Zhao ◽  
Long Yi ◽  
Minghe Shen ◽  
Chao Wang ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Conformational Changes ◽  
Magnaporthe Oryzae ◽  
Structural Information ◽  
Complex Structure ◽  
Critical Role ◽  
Catalytic Process ◽  
Structural Basis ◽  
Salt Bridges ◽  
Terminal Domain

Trehalose-6-phosphate (T6P) synthase (Tps1) catalyzes the formation of T6P from UDP-glucose (UDPG) (or GDPG, etc.) and glucose-6-phosphate (G6P), and structural basis of this process has not been well studied. MoTps1 (Magnaporthe oryzae Tps1) plays a critical role in carbon and nitrogen metabolism, but its structural information is unknown. Here we present the crystal structures of MoTps1 apo, binary (with UDPG) and ternary (with UDPG/G6P or UDP/T6P) complexes. MoTps1 consists of two modified Rossmann-fold domains and a catalytic center in-between. Unlike Escherichia coli OtsA (EcOtsA, the Tps1 of E. coli), MoTps1 exists as a mixture of monomer, dimer, and oligomer in solution. Inter-chain salt bridges, which are not fully conserved in EcOtsA, play primary roles in MoTps1 oligomerization. Binding of UDPG by MoTps1 C-terminal domain modifies the substrate pocket of MoTps1. In the MoTps1 ternary complex structure, UDP and T6P, the products of UDPG and G6P, are detected, and substantial conformational rearrangements of N-terminal domain, including structural reshuffling (β3–β4 loop to α0 helix) and movement of a ‘shift region' towards the catalytic centre, are observed. These conformational changes render MoTps1 to a ‘closed' state compared with its ‘open' state in apo or UDPG complex structures. By solving the EcOtsA apo structure, we confirmed that similar ligand binding induced conformational changes also exist in EcOtsA, although no structural reshuffling involved. Based on our research and previous studies, we present a model for the catalytic process of Tps1. Our research provides novel information on MoTps1, Tps1 family, and structure-based antifungal drug design.

Characterization of a Mode of Specific Binding of Fibrin Monomer through its Amino-Terminal Domain by Macrophages and Macrophage Cell-Lines

1990 ◽  
Vol 63 (02) ◽  
pp. 193-203 ◽  
Author(s):  
John R Shainoff ◽  
Deborah J Stearns ◽  
Patricia M DiBello ◽  
Youko Hishikawa-Itoh
Keyword(s):  
Peritoneal Macrophages ◽  
Affinity Binding ◽  
Macrophage Cell ◽  
High Affinity Binding ◽  
Amino Terminal ◽  
High Affinity ◽  
Terminal Domain ◽  
Weak Binding ◽  
Amino Terminal Domain

SummaryThe studies reported here probe the existence of a receptor-mediated mode of fibrin-binding by macrophages that is associated with the chemical change underlying the fibrinogen-fibrin conversion (the release of fibrinopeptides from the amino-terminal domain) without depending on fibrin-aggregation. The question is pursued by 1) characterization of binding in relation to fibrinopeptide content of both the intact protein and the CNBr-fragment comprising the amino-terminal domain known as the NDSK of the protein, 2) tests of competition for binding sites, and 3) photo-affinity labeling of macrophage surface proteins. The binding of intact monomers of types lacking either fibrinopeptide A alone (α-fibrin) or both fibrinopeptides A and B (αβ-fibrin) by peritoneal macrophages is characterized as proceeding through both a fibrin-specific low density/high affinity (BMAX ≃ 200–800 molecules/cell, KD ≃ 10−12 M) interaction that is not duplicated with fibrinogen, and a non-specific high density/low affinity (BMAX ≥ 105 molecules/cell, KD ≥ 10−6 M) interaction equivalent to the weak binding of fibrinogen. Similar binding characteristics are displayed by monocyte/macrophage cell lines (J774A.1 and U937) as well as peritoneal macrophages towards the NDSK preparations of these proteins, except for a slightly weaker (KD ≃ 10−10 M) high-affinity binding. The high affinity binding of intact monomer is inhibitable by fibrin-NDSK, but not fibrinogen-NDSK. This binding appears principally dependent on release of fibrinopeptide-A, because a species of fibrin (β-fibrin) lacking fibrinopeptide-B alone undergoes only weak binding similar to that of fibrinogen. Synthetic Gly-Pro-Arg and Gly-His-Arg-Pro corresponding to the N-termini of to the α- and the β-chains of fibrin both inhibit the high affinity binding of the fibrin-NDSKs, and the cell-adhesion peptide Arg-Gly-Asp does not. Photoaffinity-labeling experiments indicate that polypeptides with elec-trophoretically estimated masses of 124 and 187 kDa are the principal membrane components associated with specifically bound fibrin-NDSK. The binding could not be up-regulated with either phorbol myristyl acetate, interferon gamma or ADP, but was abolished by EDTA and by lipopolysaccharide. Because of the low BMAX, it is suggested that the high-affinity mode of binding characterized here would be too limited to function by itself in scavenging much fibrin, but may act cooperatively with other, less limited modes of fibrin binding.

Is the Rigidity of SARS-CoV-2 Spike Receptor-Binding Motif the Hallmark for Its Enhanced Infectivity and Pathogenesis?

2020 ◽  
Author(s):  
Angelo Spinello ◽  
Andrea Saltalamacchia ◽  
Alessandra Magistrato
Keyword(s):  
Health Economic ◽  
Global Health ◽  
Receptor Binding ◽  
Binding Motif ◽  
Spike Glycoprotein ◽  
High Affinity ◽  
Global Pandemic ◽  
Medical Countermeasures ◽  
High Infectivity ◽  
Human Receptor

<p>The latest outbreak of a new pathogenic coronavirus (SARS-CoV-2) is provoking a global health, economic and societal crisis. All-atom simulations enabled us to uncover the key molecular traits underlying the high affinity of SARS-CoV-2 spike glycoprotein towards its human receptor, providing a rationale to its high infectivity. Harnessing this knowledge can boost developing effective medical countermeasures to fight the current global pandemic.</p>

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