This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1n69
From Proteopedia
Crystal structure of human saposin B
Overview
Saposin 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 alpha-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.
About this Structure
1N69 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of saposin B reveals a dimeric shell for lipid binding., Ahn VE, Faull KF, Whitelegge JP, Fluharty AL, Prive GG, Proc Natl Acad Sci U S A. 2003 Jan 7;100(1):38-43. Epub 2002 Dec 23. PMID:12518053 Page seeded by OCA on Sat May 3 02:08:52 2008
