Endosome rupture enables enteroviruses from the family Picornaviridae to infect cells.

Membrane penetration by non-enveloped viruses is diverse and generally not well understood. Enteroviruses, one of the largest groups of non-enveloped viruses, cause diseases ranging from the common cold to life-threatening encephalitis. Enteroviruses enter cells by receptor-mediated endocytosis.

Structure and replication of Pseudomonas aeruginosa phage JBD30.

Bacteriophages are the most abundant biological entities on Earth, but our understanding of many aspects of their lifecycles is still incomplete. Here, we have structurally analysed the infection cycle of the siphophage Casadabanvirus JBD30. Using its baseplate, JBD30 attaches to Pseudomonas aeruginosa via the bacterial type IV pilus, whose subsequent retraction brings the phage to the bacterial cell surface.

The structure of immature tick-borne encephalitis virus supports the collapse model of flavivirus maturation.

We present structures of three immature tick-borne encephalitis virus (TBEV) isolates. Our atomic models of the major viral components, the E and prM proteins, indicate that the pr domains of prM have a critical role in holding the heterohexameric prM3E3 spikes in a metastable conformation. Destabilization of the prM furin-sensitive loop at acidic pH facilitates its processing.

Structure and replication cycle of a virus infecting climate-modulating alga .

The globally distributed marine alga has cooling effect on the Earth's climate. The population density of is restricted by viruses, including virus 201 (EhV-201). Despite the impact of viruses on the climate, there is limited information about their structure and replication.

Are kuravirus capsid diameters quantized? The first all-atom genome tracing method for double-stranded DNA viruses.

The revolution in cryo-electron microscopy has resulted in unprecedented power to resolve large macromolecular complexes including viruses. Many methods exist to explain density corresponding to proteins and thus entire protein capsids have been solved at the all-atom level. However methods for nucleic acids lag behind, and no all-atom viral double-stranded DNA genomes have been published at all.

Feasibility of Mouth-to-Mouth Ventilation through FPP2 Respirator in BLS Training during COVID-19 Pandemic (MOVERESP Study): Simulation-Based Study.

Background: Due to the COVID-19 pandemic, Basic Life Support (BLS) training has been limited to compression-only or bag-mask ventilation. The most breathable nanofiber respirators carry the technical possibility for inflation of the mannequin. The aim of this study was to assess the efficacy of mouth-to-mouth breathing through a FFP2 respirator during BLS.

Virion structure of Leishmania RNA virus 1.

The presence of Leishmania RNA virus 1 (LRV1) enables Leishmania protozoan parasites to cause more severe disease than the virus-free strains. The structure of LRV1 virus-like particles has been determined previously, however, the structure of the LRV1 virion has not been characterized. Here we used cryo-electron microscopy and single-particle reconstruction to determine the structures of the LRV1 virion and empty particle isolated from Leishmania guyanensis to resolutions of 4.

Polyelectrolyte coating of cryo-EM grids improves lateral distribution and prevents aggregation of macromolecules.

Cryo-electron microscopy (cryo-EM) is one of the primary methods used to determine the structures of macromolecules and their complexes. With the increased availability of cryo-electron microscopes, the preparation of high-quality samples has become a bottleneck in the cryo-EM structure-determination pipeline. Macromolecules can be damaged during the purification or preparation of vitrified samples for cryo-EM, making them prone to binding to the grid support, to aggregation or to the adoption of preferential orientations at the air-water interface.

Tail proteins of phage SU10 reorganize into the nozzle for genome delivery.

Escherichia coli phage SU10 belongs to the genus Kuravirus from the class Caudoviricetes of phages with short non-contractile tails. In contrast to other short-tailed phages, the tails of Kuraviruses elongate upon cell attachment. Here we show that the virion of SU10 has a prolate head, containing genome and ejection proteins, and a tail, which is formed of portal, adaptor, nozzle, and tail needle proteins and decorated with long and short fibers.

Cryo-electron microscopy and image classification reveal the existence and structure of the coxsackievirus A6 virion.

Coxsackievirus A6 (CV-A6) has recently overtaken enterovirus A71 and CV-A16 as the primary causative agent of hand, foot, and mouth disease worldwide. Virions of CV-A6 were not identified in previous structural studies, and it was speculated that the virus is unique among enteroviruses in using altered particles with expanded capsids to infect cells. In contrast, the virions of other enteroviruses are required for infection.

Structures of L-BC virus and its open particle provide insight into Totivirus capsid assembly.

L-BC virus persists in the budding yeast Saccharomyces cerevisiae, whereas other viruses from the family Totiviridae infect a diverse group of organisms including protists, fungi, arthropods, and vertebrates. The presence of totiviruses alters the fitness of the host organisms, for example, by maintaining the killer system in yeast or increasing the virulence of Leishmania guyanensis. Despite the importance of totiviruses for their host survival, there is limited information about Totivirus structure and assembly.

Structure of Human Enterovirus 70 and Its Inhibition by Capsid-Binding Compounds.

Enterovirus 70 (EV70) is a human pathogen belonging to the family . EV70 is transmitted by eye secretions and causes acute hemorrhagic conjunctivitis, a serious eye disease. Despite the severity of the disease caused by EV70, its structure is unknown.

Epitope convergence of broadly HIV-1 neutralizing IgA and IgG antibody lineages in a viremic controller.

Decrypting the B cell ontogeny of HIV-1 broadly neutralizing antibodies (bNAbs) is paramount for vaccine design. Here, we characterized IgA and IgG bNAbs of three distinct B cell lineages in a viremic controller, two of which comprised only IgG+ or IgA+ blood memory B cells; the third combined both IgG and IgA clonal variants. 7-269 bNAb in the IgA-only lineage displayed the highest neutralizing capacity despite limited somatic mutation, and delayed viral rebound in humanized mice.

SARS-CoV-2 rapid antigen tests provide benefits for epidemic control - observations from Austrian schools.

Objective: This paper motivates and justifies the use of antigen tests for epidemic control as distinct from a diagnostic test.

Study Design And Setting: We discuss the relative advantages of antigen and PCR tests, summarizing evidence from both the literature as well as Austrian schools, which conducted frequent, mass rapid antigen testing during the spring of 2021. While our report on testing predates Delta, we have updated the review with recent data on viral loads in breakthrough infections and more information about testing efficacy, especially in children.

Cargo Release from Nonenveloped Viruses and Virus-like Nanoparticles: Capsid Rupture or Pore Formation.

Virus-like nanoparticles are protein shells similar to wild-type viruses, and both aim to deliver their content into a cell. Unfortunately, the release mechanism of their cargo/genome remains elusive. Pores on the symmetry axes were proposed to enable the slow release of the viral genome.

Demonstration of the role of cell wall homeostasis in growth and the action of bactericidal antibiotics.

Bacterial cell wall peptidoglycan is essential, maintaining both cellular integrity and morphology, in the face of internal turgor pressure. Peptidoglycan synthesis is important, as it is targeted by cell wall antibiotics, including methicillin and vancomycin. Here, we have used the major human pathogen to elucidate both the cell wall dynamic processes essential for growth (life) and the bactericidal effects of cell wall antibiotics (death) based on the principle of coordinated peptidoglycan synthesis and hydrolysis.

ICAM-1 induced rearrangements of capsid and genome prime rhinovirus 14 for activation and uncoating.

Most rhinoviruses, which are the leading cause of the common cold, utilize intercellular adhesion molecule-1 (ICAM-1) as a receptor to infect cells. To release their genomes, rhinoviruses convert to activated particles that contain pores in the capsid, lack minor capsid protein VP4, and have an altered genome organization. The binding of rhinoviruses to ICAM-1 promotes virus activation; however, the molecular details of the process remain unknown.

Virion structure and genome release mechanism of dicistrovirus Kashmir bee virus.

Infections of Kashmir bee virus (KBV) are lethal for honeybees and have been associated with colony collapse disorder. KBV and closely related viruses contribute to the ongoing decline in the number of honeybee colonies in North America, Europe, Australia, and other parts of the world. Despite the economic and ecological impact of KBV, its structure and infection process remain unknown.

Capsid opening enables genome release of iflaviruses.

The family Iflaviridae includes economically important viruses of the western honeybee such as deformed wing virus, slow bee paralysis virus, and sacbrood virus. Iflaviruses have nonenveloped virions and capsids organized with icosahedral symmetry. The genome release of iflaviruses can be induced in vitro by exposure to acidic pH, implying that they enter cells by endocytosis.

Capsid Structure of RNA Virus 1.

parasites cause a variety of symptoms, including mucocutaneous leishmaniasis, which results in the destruction of the mucous membranes of the nose, mouth, and throat. The species of carrying RNA virus 1 (LRV1), from the family , are more likely to cause severe disease and are less sensitive to treatment than those that do not contain the virus. Although the importance of LRV1 for the severity of leishmaniasis was discovered a long time ago, the structure of the virus remained unknown.

Virion structures and genome delivery of honeybee viruses.

The western honeybee is the primary pollinator of numerous food crops. Furthermore, honeybees are essential for ecosystem stability by sustaining the diversity and abundance of wild flowering plants. However, the worldwide population of honeybees is under pressure from environmental stress and pathogens.

Structure and mechanism of DNA delivery of a gene transfer agent.

Alphaproteobacteria, which are the most abundant microorganisms of temperate oceans, produce phage-like particles called gene transfer agents (GTAs) that mediate lateral gene exchange. However, the mechanism by which GTAs deliver DNA into cells is unknown. Here we present the structure of the GTA of Rhodobacter capsulatus (RcGTA) and describe the conformational changes required for its DNA ejection.

A molecular clone of Chronic Bee Paralysis Virus (CBPV) causes mortality in honey bee pupae (Apis mellifera).

Among the many diseases compromising the well-being of the honey bee (Apis mellifera) the chronic paralysis syndrome of adult honey bees is one of the best described. The causative agent, chronic bee paralysis virus (CBPV), is a positive sense, single-stranded RNA virus with a segmented genome. Segment 1 encodes three putative open reading frames (ORFs), including the RNA-dependent RNA polymerase and other non-structural protein coding regions.

Structure and genome ejection mechanism of phage P68.

Phages infecting can be used as therapeutics against antibiotic-resistant bacterial infections. However, there is limited information about the mechanism of genome delivery of phages that infect Gram-positive bacteria. Here, we present the structures of native phage P68, genome ejection intermediate, and empty particle.