The peplomer protein sequence of the M41 strain of coronavirus IBV and its comparison with Beaudette strains

The amino acid sequence of the gene for the peplomer protein of the vaccine strain M41 and the Beaudette laboratory strain M42-Salk of avian infectious bronchitis virus (IBV) have been derived from cDNA sequences. As found with other coronaviruses, the peplomer protein carries the epitopes eliciting neutralizing antibodies. The gene encodes a primary translation product of 1162 amino acids with a molecular weight of 128079. The use of a recent algorithm to predict membrane-protein interactions led to the unambiguous localization of the signah peptide and a transmembrane anchor α-helix at the C-terminus. At 50 positions amino acid differences were found between M41 and two Beaudette strains (M42-Salk and M42-Houghton). They are partly clustered in two regions of the protein. These two regions are candidates for neutralization epitopes of the protein.