4DDJ

Crystal structure of saposin A in complex with lauryldimethylamine-N-oxide (LDAO)

4DDJ の概要

• エントリーDOI: 10.2210/pdb4ddj/pdb
• 関連するPDBエントリー: 2DOB
• 分子名称: Saposin-A, LAURYL DIMETHYLAMINE-N-OXIDE (3 entities in total)
• 機能のキーワード: saposin fold, sphingolipid activator protein, galactosylceramide, lauryldimethylamine-n-oxide, lipid, detergent, lysosome, lipid binding protein
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 13649.53

構造登録者

Popovic, K.,Prive, G.G. (登録日: 2012-01-18, 公開日: 2012-02-15, 最終更新日: 2024-11-20)

主引用文献

Popovic, K.,Holyoake, J.,Pomes, R.,Prive, G.G.
Structure of saposin A lipoprotein discs.
Proc.Natl.Acad.Sci.USA, 109:2908-2912, 2012

PubMed Abstract: The saposins are small, membrane-active proteins that exist in both soluble and lipid-bound states. Saposin A has roles in sphingolipid catabolism and transport and is required for the breakdown of galactosylceramide by β-galactosylceramidase. In the absence of lipid, saposin A adopts a closed monomeric apo conformation typical of this family. To study a lipid-bound state of this protein, we determined the crystal structure of saposin A in the presence of detergent to 1.9 Å resolution. The structure reveals two chains of saposin A in an open conformation encapsulating 40 internally bound detergent molecules organized in a highly ordered bilayer-like hydrophobic core. The complex provides a high-resolution view of a discoidal lipoprotein particle in which all of the internalized acyl chains are resolved. Saposin A lipoprotein discs exhibit limited selectivity with respect to the incorporated lipid, and can solubilize phospholipids, sphingolipids, and cholesterol into discrete, monodisperse particles with mass of approximately 27 kDa. These discs may be the smallest possible lipoprotein structures that are stabilized by lipid self-assembly.

PubMed: 22308394
DOI: 10.1073/pnas.1115743109

実験手法

X-RAY DIFFRACTION (1.9 Å)