The pre-fusion structure of Herpes simplex virus glycoprotein B

Cell entry of enveloped viruses requires specialized viral proteins which mediate fusion with the host membrane by substantial structural rearrangements from a metastable pre- to a stable postfusion conformation. This metastability renders the Herpes simplex virus (HSV-1) fusion glycoprotein B (gB) highly unstable such that it readily converts into the post-fusion form, thereby precluding structural elucidation of the pharmacologically relevant pre-fusion conformation. By identification of conserved sequence signatures and molecular dynamics simulations, we devised a mutation that stabilized this form. Functionally locking gB, allowed the structural determination of its membrane-embedded pre-fusion conformation at sub-nanometer resolution and enabled the unambiguous fit of all ectodomains. The resulting pseudo-atomic model reveals a striking conservation of conformational domain rearrangements during fusion between HSV-1 gB and the Vesicular Stomatitis Virus glycoprotein G (VSV-G) despite their very distant phylogeny. In combination with our comparative sequence-structure analysis, these findings suggest common fusogenic domain rearrangements in all class III viral fusion proteins. Rey, M. Topf, K

Variegated squirrel bornavirus 1 in squirrels, Germany and the Netherlands

We screened squirrels in Germany and the Netherlands for the novel zoonotic variegated squirrel bornavirus 1 (VSBV-1). The detection of VSBV-1 in 11 squirrels indicates a considerable risk for transmission to humans handling those animals. Therefore, squirrels in contact with humans should routinely be tested for VSBV-1

The European Virus Archive goes global: A growing resource for research

The European Virus Archive (EVA) was created in 2008 with funding from the FP7-EU Infrastructure Programme, in response to the need for a coordinated and readily accessible collection of viruses that could be made available to academia, public health organisations and industry. Within three years, it developed from a consortium of nine European laboratories to encompass associated partners in Africa, Russia, China, Turkey, Germany and Italy. In 2014, the H2020 Research and Innovation Framework Programme (INFRAS projects) provided support for the transformation of the EVA from a European to a global organization (EVAg). The EVAg now operates as a non-profit consortium, with 26 partners and 20 associated partners from 21 EU and non-EU countries. In this paper, we outline the structure, management and goals of the EVAg, to bring to the attention of researchers the wealth of products it can provide and to illustrate how end-users can gain access to these resources. Organisations or individuals who would like to be considered as contributors are invited to contact the EVAg coordinator, Jean-Louis Romette, at [email protected]

Dimerization Induced Allosteric Changes of the Oxyanion Hole Loop Activate the Pseudorabies Virus Assemblin pUL26N, a Herpesvirus Serine Protease

Herpesviruses encode a characteristic serine protease with a unique fold and an active site that comprises the unusual triad Ser-His-His. The protease is essential for viral replication and as such constitutes a promising drug target. In solution, a dynamic equilibrium exists between an inactive monomeric and an active dimeric form of the enzyme, which is believed to play a key regulatory role in the orchestration of proteolysis and capsid assembly. Currently available crystal structures of herpesvirus proteases correspond either to the dimeric state or to complexes with peptide mimetics that alter the dimerization interface. In contrast, the structure of the native monomeric state has remained elusive. Here, we present the three-dimensional structures of native monomeric, active dimeric, and diisopropyl fluorophosphate-inhibited dimeric protease derived from pseudorabies virus, an alphaherpesvirus of swine. These structures, solved by X-ray crystallography to respective resolutions of 2.05, 2.10 and 2.03 Å, allow a direct comparison of the main conformational states of the protease. In the dimeric form, a functional oxyanion hole is formed by a loop of 10 amino-acid residues encompassing two consecutive arginine residues (Arg136 and Arg137); both are strictly conserved throughout the herpesviruses. In the monomeric form, the top of the loop is shifted by approximately 11 Å, resulting in a complete disruption of the oxyanion hole and loss of activity. The dimerization-induced allosteric changes described here form the physical basis for the concentration-dependent activation of the protease, which is essential for proper virus replication. Small-angle X-ray scattering experiments confirmed a concentration-dependent equilibrium of monomeric and dimeric protease in solution

Self-government, memory & strife Negotiating the past in selected villages of mountainous Evritania

SIGLEAvailable from British Library Document Supply Centre-DSC:DX193417 / BLDSC - British Library Document Supply CentreGBUnited Kingdo