Download MendeleyCrystal structure of saposin D in an open conformation.
Gebai, A., Gorelik, A., Nagar, B.(2018) J Struct Biol 204: 145-150
- PubMed: 30026085
- DOI: https://doi.org/10.1016/j.jsb.2018.07.011
- Primary Citation of Related Structures:
5U85 - PubMed Abstract:
Saposins are accessory proteins that aid in the degradation of sphingolipids by hydrolytic enzymes. Their structure usually comprises four α-helices arranged in various conformations including an open, V-shaped form that is generally associated with the ability to interact with membranes and/or enzymes to accentuate activity. Saposin D is required by the lysosomal hydrolase, acid ceramidase, which breaks down ceramide into sphingosine and free fatty acid, to display optimal activity. The structure of saposin D was previously determined in an inactive conformation, revealing a monomeric, closed and compact form. Here, we present the crystal structure of the open, V-shaped form of saposin D. The overall shape is similar to the open conformation found in other saposins with slight differences in the angles between the α-helices. The structure forms a dimer that serves to stabilize the hydrophobic surface exposed in the open form, which results in an internal, hydrophobic cavity that could be used to carry extracted membrane lipids.
Organizational Affiliation:
Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, QC H3G 0B1, Canada.
