Insights from molecular structure predictions of the infectious bronchitis virus S1 spike glycoprotein.
Infectious bronchitis virus is an important respiratory pathogen in chickens. The IBV S1 spike is a viral structural protein that is responsible for attachment to host receptors and is a major target for neutralizing antibodies. To date, there is no experimentally determined structure for the IBV S1 spike. In this study, we sought to find a predicted tertiary structure for IBV S1 using I-TASSER, which is an automated homology modeling platform. We found that the predicted structures obtained were robust and consistent with experimental data. For instance, we observed that all four residues (38, 43, 63, and 68) that have been shown to be critical for binding to host tissues, were found at the surface of the predicted structure of Massachusetts (Mass) S1 spike. Together with antigenicity index analysis, we were also able to show that Ma5 vaccine has higher antigenicity indices at residues close to the receptor-binding region than M41 vaccine, thereby providing a possible mechanism on how Ma5 achieves better protection against challenge. Examination of the predicted structure of the Arkansas IBV S1 spike also gave insights on the effect of polymorphisms at position 43 on the surface availability of receptor binding residues. This study showcases advancements in protein structure prediction and contributes useful, inexpensive tools to provide insights into the biology of IBV.
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, United States.
Christina Lora M
CLM
Leyson
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, United States; Poultry Science Department, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, United States.
Brian J
BJ
Jordan
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, United States. Electronic address: mjackwoo@uga.edu.
Mark W
MW
Jackwood
D019295:Computational Biology; D001351:Infectious bronchitis virus / Q000737:chemistry*; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D012984:Software; D064370:Spike Glycoprotein, Coronavirus / Q000737:chemistry* / Q000378:metabolism*
D064370:Spike Glycoprotein, Coronavirus
Arkansas IBV; Infectious bronchitis virus (IBV); Massachusetts IBV; Protein structure prediction; S1 spike; Spike glycoprotein