Deduced amino acid sequences of the HA protein of equine H5N1 isolate in comparison to closely related Egyptian HPAIV H5N1 isolates. Dots denote identical amino acids, which are given in one-letter code. Consensus sequences for N-glycosylation (NXS or NXT, except where X = P) are underlined. Boxed segments indicate the signal peptide and the polybasic proteolytic cleavage motif, respectively. Shaded letters denote potential sites responsible for receptor binding sites (H3 influenza numbering).