pfam03489: SapB_2 (This model is not part of the current CDD release)
Saposin-like type B, region 2
Saposin B is a small non-enzymatic glycoprotein required for the breakdown of cerebroside sulphates (sulphatides) in lysosomes. Saposin B contains three intramolecular disulphide bridges, exists as a dimer and is remarkably heat, protease and pH stable. The crystal structure of human saposin B reveals an unusual shell-like dimer consisting of a monolayer of alpha-helices enclosing a large hydrophobic cavity. It is one of the most studied members of the saposin protein family and it is involved in the hydrolyzis of glycolipids and glycerolipids. SapB is unique in the saposin family in that it facilitates degradation by interacting with the substrate, not the enzymes.
Jiyao W et al.(2023). "The conserved domain database in 2023.",