Figure 2. Amino acid sequence alignment of the fusion (F) protein of various human metapneumovirus (HMPV) strains and other paramyxoviruses. Amino acid numbering is based on the sequence of the HMPV strain NETH-001 (GenBank accession no. AF371337). Amino acids shown are those different than NETH-001. Boxed residues represent conserved cysteines. Potential N-glycosylation sites are underlined. The fusion domain is indicated by italics in the consensus sequence, whereas the heptad repeat A region is indicated by bold characters. Shaded residues represent significant substitutions between HMPV groups and subgroups. Note that only distinct HMPV strains were included in the alignment. PVM, pneumonia virus of mice; BRSV, bovine respiratory syncytial virus; HRSV, human respiratory syncytial virus; APV, avian pneumovirus; RSA, Republic of South Africa; CAN, Canada; FRA, France; AUS, Australia; NETH, the Netherlands.