Ahn, Victoria E.Faull, Kym F.Whitelegge, Julian P.2021-09-302021-09-302003hn, V. E. et al. (2003). Crystal structure of saposin B reveals a dimeric shell for lipid binding. Proceedings of the National Academy of Sciences of the United States of America, 100(1), 38–43. https://doi.org/10.1073/pnas.01369471001091-6490http://hdl.handle.net/10566/6842Saposin B is a small, nonenzymatic glycosphingolipid activator protein required for the breakdown of cerebroside sulfates (sulfatides) within the lysosome. The protein can extract target lipids from membranes, forming soluble protein-lipid complexes that are recognized by arylsulfatase A. The crystal structure of human saposin B reveals an unusual shell-like dimer consisting of a monolayer of -helices enclosing a large hydrophobic cavity. Although the secondary structure of saposin B is similar to that of the known monomeric members of the saposin-like superfamily, the helices are repacked into a different tertiary arrangement to form the homodimer. A comparison of the two forms of the saposin B dimer suggests that extraction of target lipids from membranes involves a conformational change that facilitates access to the inner cavity.enChemistryLipid bindingProteinSaposin BArticle