research papers
Saposin D is a sphingolipid activator protein required for the lysosomal breakdown of ceramide to a fatty acid and sphingosine by acid ceramidase. The crystal structure of saposin D has been determined in two different crystal forms, resulting in a total of six crystallographically independent views of this small 80-amino-acid protein. All of the structures are highly similar and reveal the monomeric form of the saposin fold previously seen in the crystal structures of saposins A and C. Saposin D is slightly more compact than the related saposins A and C owing to a slight repositioning of the `stem' and `hairpin' regions of the protein.
Supporting information
PDB references: saposin D, orthorhombic, 3bqp, r3bqpsf; triclinic, 3bqq, r3bqqsf