RESEARCH ARTICLE Cryo-EM structure of infectious bronchitis coronavirus spike protein reveals structural and functional evolution of coronavirus spike proteins Jian Shang1☯, Yuan Zheng1☯, Yang Yang1☯, Chang Liu1, Qibin Geng1, Chuming Luo1, Wei Zhang2,3, Fang Li1* 1 Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States of America, 2 Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, United States of America, 3 Characterization Facility, College of Science and Engineering, University of Minnesota, Minneapolis, MN, United States of America ☯ These authors contributed equally to this work. *