Amino acid sequence alignment of tetherins. The amino acid sequences of feline, canine (transcript variant 2), human, rat and horse tetherin are compared. Amino acids conserved between all tetherin orthologs are highlighted in dark grey, those conserved between at least three sequences in light grey. The positions of predicted protein domains are indicated. The position of the transmembrane domain is marked by a blue bar and the position of the coiled-coil domain, which contains the three conserved cysteine residues, by a green bar. The length of the extracellular domain is indicated by black arrows. The position of the potential GPI anchor attachment site (ω-site) is marked by a blue arrow.