In-depth Bioinformatic Analyses of Human SARS-CoV-2, SARS-CoV, MERS-CoV, and Other Nidovirales Suggest Important Roles of Noncanonical Nucleic Acid Structures in Their Lifecycles

Martin Bartas; Václav Brázda; Natália Bohálová; Alessio Cantara; Adriana Volná; Tereza Stachurová; Katerina Malachová; Eva B. Jagelská; Otília Porubiaková; Jirí Cerven; Petr Pecinka

According to the current state of knowledge, the order Nidovirales can be divided into six distinct families, and there are two unclassified species (Figure 2) . Coronaviridae is the largest family and consists of 56 species. Among these are 12 species able to infect humans, including SARS-CoV, MERS-CoV, and SARS-CoV-2. Second largest is the Arteriviridae family with 22 species, third largest is the Mesnidovirineae family with 13 species, fourth is the Tobaniviridae family with 11 species, . CC-BY-ND 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.09.031252 doi: bioRxiv preprint including 1 species able to infect humans. Fifth largest is the Ronidovirineae family with 5 species, and sixth is the Mononiviridae family with only 1 species. FIGURE 2 | Phylogenetic relationships in Nidovirales. SARS-CoV-2 is not yet recognized by iToL, but, based upon current evidence, it probably will be placed close to the Bat Hpbetacoronavirus/Zheijang2013 and Severe acute respiratory syndrome-related coronavirus (SARS-nCoV) branches (Lu et al., 2020) . The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.09.031252 doi: bioRxiv preprint