Influenza a virus antiparallel helical nucleocapsid-like pseudo-atomic structure.

Influenza A viruses are responsible for human seasonal epidemics and severe animal pandemics with a risk of zoonotic transmission to humans. The viral segmented RNA genome is encapsidated by nucleoproteins (NP) and attached to the heterotrimeric polymerase, forming the viral ribonucleoproteins (vRNPs). Flexible helical vRNPs are central for viral transcription and replication.

Crystal structure and solution state of the C-terminal head region of the narmovirus receptor binding protein.

Genetically diverse paramyxoviruses are united in their presentation of a receptor-binding protein (RBP), which works in concert with the fusion protein to facilitate host-cell entry. The C-terminal head region of the paramyxoviral RBP, a primary determinant of host-cell tropism and inter-species transmission potential, forms structurally distinct classes dependent upon protein and glycan receptor specificity. Here, we reveal the architecture of the C-terminal head region of the RBPs from Nariva virus (NarV) and Mossman virus (MosV), two archetypal rodent-borne paramyxoviruses within the recently established genus , family .

Unraveling virus relationships by structure-based phylogenetic classification.

Delineation of the intricacies of protein function from macromolecular structure constitutes a continual obstacle in the study of cell and pathogen biology. Structure-based phylogenetic analysis has emerged as a powerful tool for addressing this challenge, allowing the detection and quantification of conserved architectural properties between proteins, including those with low or no detectable sequence homology. With a focus on viral protein structure, we highlight how a number of investigations have utilized this powerful method to infer common functionality and ancestry.

A structure-based rationale for sialic acid independent host-cell entry of Sosuga virus.

The bat-borne paramyxovirus, Sosuga virus (SosV), is one of many paramyxoviruses recently identified and classified within the newly established genus , family The envelope surface of SosV presents a receptor-binding protein (RBP), SosV-RBP, which facilitates host-cell attachment and entry. Unlike closely related hemagglutinin neuraminidase RBPs from other genera of the , SosV-RBP and other pararubulavirus RBPs lack many of the stringently conserved residues required for sialic acid recognition and hydrolysis. We determined the crystal structure of the globular head region of SosV-RBP, revealing that while the glycoprotein presents a classical paramyxoviral six-bladed β-propeller fold and structurally classifies in close proximity to paramyxoviral RBPs with hemagglutinin-neuraminidase (HN) functionality, it presents a receptor-binding face incongruent with sialic acid recognition.

Cross-Reactive and Cross-Neutralizing Activity of Human Mumps Antibodies Against a Novel Mumps Virus From Bats.

To evaluate the antigenic relationship between bat mumps virus (BMV) and the JL5 vaccine strain of mumps virus (MuVJL5), we rescued a chimeric virus bearing the F and HN glycoproteins of BMV in the background of a recombinant JL5 genome (rMuVJL5). Cross-reactivity and cross-neutralization between this chimeric recombinant MuV bearing the F and HN glycoproteins of BMV (rMuVJL5-F/HNBMV) virus and rMuVJL5 were demonstrated using hyperimmune mouse serum samples and a curated panel of human serum. All mouse and human serum samples that were able to neutralize rMuVJL5 infection had cross-neutralizing activity against rMuVJL5-F/HNBMV.