bioRxiv preprint doi: https://doi.org/10.1101/2020.04.09.031252; this version posted April 11, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 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 Bartas1,#, Václav Brázda2,3,#, Natália Bohálová2,4, Alessio Cantara2,4, Adriana Volná5 Tereza Stachurová1, Kateřina Malachová1, Eva B. Jagelská2, Otília Porubiaková2,3, Jiří Červeň1 and Petr Pečinka1,* 1Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic 2Department of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic 3Brno University of Technology, Faculty of Chemistry, Brno, Czech Republic 4Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic 5Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czech Republic * Correspondence: Corresponding Author,
[email protected] # These authors contributed equally to this work. Keywords: coronavirus, genome, RNA, G-quadruplex, inverted repeats Abstract Noncanonical nucleic acid structures play important roles in the regulation of molecular processes. Considering the importance of the ongoing coronavirus crisis, we decided to evaluate genomes of all coronaviruses sequenced to date (stated more broadly, the order Nidovirales) to determine if they contain noncanonical nucleic acid structures. We discovered much evidence of putative G-quadruplex sites and even much more of inverted repeats (IRs) loci, which in fact are ubiquitous along the whole genomic sequence and indicate a possible mechanism for genomic RNA packaging.