Sialidase 4 (SIAL4)

SIAL4 belongs to a family of glycohydrolytic enzymes, which remove terminal sialic acid residues from various sialo derivatives, such as glycoproteins, glycolipids, oligosaccharides, and gangliosides.The NEU4 sequence has a high GC content (70%). The deduced 484-amino acid NEU4 protein has a calculated molecular mass of 51.6 kD. It contains 2 putative transmembrane regions, an N-terminal sialidase motif, 2 classical asp blocks, and a stretch of 79 amino acids that appear unique among sialidases. NEU4 also has 3 potential O-glycosylation sites and several potential phosphorylation sites. The authors predicted that the N and C termini of NEU4 are extracellular. NEU4 shares significant similarity with a 478-amino acid variant of mouse Neu4, with complete conservation of residues likely to be within the active site.