Crystal structure of saposin B reveals a dimeric shell for lipid binding
| Autor: | Victoria E. Ahn, Kym F. Faull, Gilbert G. Privé, Arvan L. Fluharty, Julian P. Whitelegge |
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| Rok vydání: | 2003 |
| Předmět: |
Models
Molecular Conformational change Sphingolipid Activator Proteins Stereochemistry Dimer Molecular Sequence Data Biology Crystallography X-Ray Protein Structure Secondary Saposins chemistry.chemical_compound Humans Amino Acid Sequence Binding site Protein secondary structure Peptide sequence Glycoproteins Multidisciplinary Binding Sites Sequence Homology Amino Acid Glycosphingolipid Biological Sciences Lipid Metabolism Cerebroside Crystallography Membrane chemistry Amino Acid Substitution Dimerization Sequence Alignment |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America. 100(1) |
| ISSN: | 0027-8424 |
| Popis: | 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 α-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. |
| Databáze: | OpenAIRE |
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