Non-viral sialidases. Sialidases or neuraminidases function to bind and hydrolyze terminal sialic acid residues from various glycoconjugates, they play vital roles in pathogenesis, bacterial nutrition and cellular interactions. They have a six-bladed, beta-propeller fold with the non-viral sialidases containing 2-5 Asp-box motifs (most commonly Ser/Thr-X-Asp-[X]-Gly-X-Thr- Trp/Phe). This CD includes eubacterial and eukaryotic sialidases.
Glycoside hydrolase family 130. Members of the glycosyl hydrolase family 130, as classified by the carbohydrate-active enzymes database (CAZY), are phosphorylases and hydrolases for beta-mannosides, and include beta-1,4-mannosylglucose phosphorylase (EC 2.4.1.281), beta-1,4-mannooligosaccharide phosphorylase (EC 2.4.1.319), beta-1,4-mannosyl-N-acetyl-glucosamine phosphorylase (EC 2.4.1.320), beta-1,2-mannobiose phosphorylase (EC 2.4.1.-), beta-1,2-oligomannan phosphorylase (EC 2.4.1.-) and beta-1,2-mannosidase (EC 3.2.1.-). They possess 5-bladed beta-propeller domains similar to families 32, 43, 62, 68, 117 (GH32, GH43, GH62, GH68, GH117). GH130 enzymes are involved in the bacterial utilization of mannans or N-linked glycans. Beta-1,4-mannosylglucose phosphorylase is involved in degradation of beta-1,4-D-mannosyl-N-acetyl-D-glucosamine linkages in the core of N-glycans; it produces alpha-mannose 1-phosphate and glucose from 4-O-beta-D-mannosyl-D-glucose and inorganic phosphate, using a critical catalytic Asp as a proton donor.