Fig. (4) Analysis of amino acid mutations in GP5 of the two NADC30-like isolates. Functional domains (black boxes) were reported according to Han et al. (2006). Extra-and intra-virion epitopes of the isolates are boxed in the consensus sequence. Two concurrent mutations (red boxes) were found at positions 32 (S32→N32) and 34 (D34→N34). Other mutations are described in the text. TM: transmembrane region.