TASK DEFINITION: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
PROBLEM: Murine norovirus-1 (MNV-1) is known to subvert host cell division inducing an accumulation of cells in the G 0 /G 1 phase, creating conditions where viral replication is favored. This study identified that NS5 (VPg), is capable of inducing cell cycle arrest in the absence of viral replication or other viral proteins in an analogous manner to MNV-1 infection. NS5 expression induced an accumulation of cells in the G 0 /G 1 phase in an asynchronous population by inhibiting progression at the G 1 /S restriction point. Furthermore, NS5 expression resulted in a down-regulation of cyclin A expression in asynchronous cells and inhibited cyclin A expression in cells progressing from G 1 to S phase. The activity of NS5 on the host cell cycle occurs through an uncharacterized function. Amino acid substitutions of NS5(Y26A) and NS5(F123A) that inhibit the ability for NS5 to attach to RNA and recruit host eukaryotic translation initiation factors, respectively, retained the ability to induce an accumulation of cells in the G 0 /G 1 phase as identified for wild-type NS5. To the best of our knowledge, this is the first report of a VPg protein manipulating the host cell cycle.

SOLUTION: Expression of the NS5 (VPg) Protein of Murine Norovirus Induces a G1/S Phase Arrest

PROBLEM: A novel betacoronavirus associated with lethal respiratory and renal complications was recently identified in patients from several countries in the Middle East. We report the deep genome sequencing of the virus directly from a patient's sputum sample. Our high-throughput sequencing yielded a substantial depth of genome sequence assembly and showed the minority viral variants in the specimen. Detailed phylogenetic analysis of the virus genome (England/ Qatar/2012) revealed its close relationship to European bat coronaviruses circulating among the bat species of the Vespertilionidae family. Molecular clock analysis showed that the 2 human infections of this betacoronavirus in June 2012 (EMC/2012) and September 2012 (England/Qatar/2012) share a common virus ancestor most likely considerably before early 2012, suggesting the human diversity is the result of multiple zoonotic events. T he ability of coronaviruses (CoVs) to infect multiple species and to rapidly change through recombination presents a continuing human health threat. The epidemic of severe acute respiratory syndrome (SARS) during 2003-2004 during which a CoV transmitted from bats to civet cats and then to humans demonstrated this potential (reviewed in [1, 2] ). Recently, a novel human betacoronavirus (betaCoV) was found to be associated with at least 13 human infections, 7 of which were fatal (3-7). One of the viruses, EMC/2012, has been sequenced, and its sequence similarity to several bat CoVs suggested an animal origin, but a definitive bat species of origin has not yet been identified (3). Additional genome sequences from this virus are needed to aid diagnostics, monitor population dynamics, identify the animal source, and characterize mechanisms of pathogenesis. The large size (30,000 nt) and high variability of CoV RNA genomes present a challenge for sequencing. We describe a strategy for rapidly designing the primers necessary for reverse transcription and cDNA amplification of such diverse RNA viruses and report the full-genome determination of the novel CoV directly from patient sputum using next-generation short-read sequencing. Full genomes from 2 epidemiologically unlinked novel CoV infections separated in time by >2 months were analyzed to gain clues to 2 major questions: what are the precursors of the virus, and how long has the virus been circulating in its current form? Materials and Methods Fifteen betaCoV full genomes with the closest homology to EMC/2012 (GenBank accession no. JX869059) were analyzed to identify all possible primer-like sequences (melting temperature 58°C-60°C, guanine plus cytosine content 35%-60%) yielding 357,198 potential primers. The 30-kb JX869059 CoV genome was divided into fifteen 2.5-kb overlapping amplicons, and the 2 highest frequency sequences mapping in the 5′ and 3′ 250 bp of each amplicon were selected. Reverse complements of the 3′ mapping sequences were prepared, resulting in a set of 60 primers for the 15 amplicons (4 primers/amplicon). Three additional primers were added for the extreme termini of the genome. The algorithm also prepared a virtual PCR map of the predicted binding and amplicon size for the primer set on CoV genomes. A map of the primer mapping positions

SOLUTION: Full-Genome Deep Sequencing and Phylogenetic Analysis of Novel Human Betacoronavirus

PROBLEM: Nonstructural protein 15 (nsp15), also called endoribonuclease, is a gene product of open reading frame 1b (ORF 1b) in coronaviruses. It is an important enzyme in the transcription/replication process involved in discontinuous negative-strand RNA synthesis. In this work, mutants of nsp15 from Human coronavirus 229E (HCoV-229E) were made based on structural analysis of the homologous nsp15s in Severe acute respiratory syndrome coronavirus (SARS-CoV) and Mouse hepatitis virus (MHV). The I26A/N52A mutant of nsp15 was overexpressed, purified and crystallized, and this mutant led to a trimeric form rather than hexamers or monomers. Crystals of trimeric nsp15 were obtained by the hanging-drop vapour-diffusion method using polyethylene glycol as a precipitant and diffracted to 2.5 Å resolution. The crystals belonged to space group C222 1 , with unit-cell parameters a = 85.9, b = 137.5, c = 423.1 Å , = = = 90 . Acta Cryst. (2015).

SOLUTION:
Crystallization and preliminary X-ray crystallographic analysis of a nonstructural protein 15 mutant from Human coronavirus 229E