Coronaviruses are responsible for upper and lower respiratory tract infections in humans. It is estimated that 1 to 10% of the population suffers annually from cold-like symptoms related to infection with human coronavirus NL63 (HCoV-NL63), an alphacoronavirus. The nucleocapsid (N) protein, the major structural component of the capsid, facilitates RNA packing, links the capsid to the envelope, and is also involved in multiple other processes, including viral replication and evasion of the immune system. Although the role of N protein in viral replication is relatively well described, no structural data are currently available regarding the N proteins of alphacoronaviruses. Moreover, our understanding of the mechanisms of RNA binding and nucleocapsid formation remains incomplete. In this study, we solved the crystal structures of the N- and C-terminal domains (NTD, residues 10 to 140, and CTD, residues 221 to 340, respectively) of the N protein of HCoV-NL63, both at a 1.5-Å resolution. Based on our structure of NTD solved here, we proposed and experimentally evaluated a model of RNA binding. The structure of the CTD reveals the mode of N protein dimerization. Overall, this study expands our understanding of the initial steps of N protein-nucleic acid interaction and may facilitate future efforts to control the associated infections. IMPORTANCE Coronaviruses are responsible for the common cold and other respiratory tract infections in humans. According to multiple studies, 1 to 10% of the population is infected each year with HCoV-NL63. Viruses are relatively simple organisms composed of a few proteins and the nucleic acids that carry the information determining their composition. The nucleocapsid (N) protein studied in this work protects the nucleic acid from the environmental factors during virus transmission. This study investigated the structural arrangement of N protein, explaining the first steps of its interaction with nucleic acid at the initial stages of virus structure assembly. The results expand our understanding of coronavirus physiology and may facilitate future efforts to control the associated infections.

In vertebrate species, the innate immune system down-regulates protein translation in response to viral infection through the action of the double-stranded RNA (dsRNA)-activated protein kinase (PKR). In some teleost species another protein kinase, Z-DNA-dependent protein kinase (PKZ), plays a similar role but instead of dsRNA binding domains, PKZ has Zα domains. These domains recognize the left-handed conformer of dsDNA and dsRNA known as Z-DNA/Z-RNA. Cyprinid herpesvirus 3 infects common and koi carp, which have PKZ, and encodes the ORF112 protein that itself bears a Zα domain, a putative competitive inhibitor of PKZ. Here we present the crystal structure of ORF112-Zα in complex with an 18-bp CpG DNA repeat, at 1.5 Å. We demonstrate that the bound DNA is in the left-handed conformation and identify key interactions for the specificity of ORF112. Localization of ORF112 protein in stress granules induced in Cyprinid herpesvirus 3-infected fish cells suggests a functional behavior similar to that of Zα domains of the interferon-regulated, nucleic acid surveillance proteins ADAR1 and DAI.

Medications and their prices are key issues for healthcare. Although access to medicines at affordable prices had been specified as a key objective of the European Health Policy, it seems that these goals have not been achieved. Therefore, we attempted an evaluation of affordability of selected medicines at full prices. The analysis concerned 2012 and was conducted between 2013 and 2015 in all the European Union (EU) countries divided into 3 groups depending on the date of their accession to the EU. Finally, we considered 9 originators used in the treatment of schizophrenia and multiple sclerosis. Information on drug prices were collected from pharmacies. Participation in the study was voluntary and anonymous in order to avoid accusations of advertising. To evaluate affordability, several factors were used (e.g. minimum earnings and Gini coefficient). Due to unavailability in some countries, the exact number of analyzed medicines varies. Drug prices vary significantly between EU Member States. Almost eleven fold difference was observed between Germany (EUR 1451.17) and Croatia (EUR 132.77) in relation to Interferone beta-1a 22 μg. Generally, prices were the highest in Germany. The cheapest drugs were found in various countries but never in the poorest ones like Bulgaria or Romania. Discrepancies in wages were observed too (the smallest minimum wage was EUR 138.00 in Bulgaria and the highest EUR 1801.00 in Luxembourg). Full price of olanzapine 5mg, however, was higher in Bulgaria (EUR 64.53) than, for instance, in Belgium (EUR 37.26). Analyzed medications are still unaffordable for many citizens of the EU. Besides, access to medicines is also impaired e.g. due to parallel trade. Unaffordability of medications may lead to the patients’ non-compliance and therefore to increased direct and indirect costs of treatment. Common European solutions are needed to achieve a real affordability and accessibility of medications.