1 Glycan shield and fusion activation of a deltacoronavirus 1 spike glycoprotein fine-tuned for enteric infections 2 3 Xiaoli Xiong1, M. Alejandra Tortorici2,3, Joost Snijder1, Craig Yoshioka4, Alexandra C. 4 Walls1, Wentao Li5, Andrew T. McGuire6, Félix A. Rey2,3, Berend-Jan Bosch5 and David 5 Veesler1*. 6 7 1Department of Biochemistry, University of Washington, Seattle, Washington 98195, 8 USA. 9 2Institut Pasteur, Unité de Virologie Structurale, Paris, France. 10 3CNRS UMR 3569 Virologie, Paris, France. 11 4Department of Biomedical Engineering, Oregon Health and Science University, 12 Portland, OR 97201, USA. 13 5Virology Division, Department of Infectious Diseases and Immunology, Faculty of 14 Veterinary Medicine, Utrecht University, 3584 CL, Utrecht, The Netherlands. 15 6Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 16 1100 Fairview Ave. N. P.O. Box 19024 Seattle, WA 98109, USA 17 18 *Correspondence: