Figure 3. Multiple sequence alignment of sialidases.

Multiple alignment of the amino acid sequences of zebrafish (Dr Neu1, Dr Neu3.1, Dr Neu3.2, Dr Neu3.3, Dr Neu3.4, Dr Neu3.5 and Dr Neu4) and human (Hs NEU1, Hs NEU2, Hs NEU3 and Hs NEU4) sialidases. The alignment was performed using the ClustalW algorithm (see the Materials and methods section). Residues that are identical are shown on a dark grey background; those on a light grey background and boxed are the conservative substitutions. The active amino acid residues derived from the crystallographic data of the human cytosolic sialidase NEU2 are indicated by asterisks (*) above the sequence. The conserved Y(F)RIP box is indicated by a grey bar under the sequences. Continuous or dotted black lines under the sequences indicate the canonical and poorly conserved Asp boxes respectively.