1O6U

The Crystal Structure of Human Supernatant Protein Factor

Summary for 1O6U

• Entry DOI: 10.2210/pdb1o6u/pdb
• Related: 1OLM
• Descriptor: SEC14-LIKE PROTEIN 2, PALMITIC ACID (3 entities in total)
• Functional Keywords: lipid transfer, cral_trio, lipid binding, transferase
• Biological source: HOMO SAPIENS (HUMAN)
• Cellular location: Cytoplasm: O76054
• Total number of polymer chains: 3
• Total formula weight: 140941.25

Authors

Stocker, A.,Schulze-Briese, C.,Tomizaki, T. (deposition date: 2002-10-16, release date: 2003-10-17, Last modification date: 2024-10-23)

Primary citation

Stocker, A.,Tomizaki, T.,Schulze-Briese, C.,Baumann, U.
Crystal Structure of Human Supernatant Protein Factor
Structure, 10:1533-, 2002

PubMed Abstract: Supernatant protein factor (SPF) promotes the epoxidation of squalene catalyzed by microsomes. Several studies suggest its in vivo role in the cholesterol biosynthetic pathway by a yet unknown mechanism. SPF belongs to a family of lipid binding proteins called CRAL_TRIO, which include yeast phosphatidylinositol transfer protein Sec14 and tocopherol transfer protein TTP. The crystal structure of human SPF at a resolution of 1.9 A reveals a two domain topology. The N-terminal 275 residues form a Sec14-like domain, while the C-terminal 115 residues consist of an eight-stranded jelly-roll barrel similar to that found in many viral protein structures. The ligand binding cavity has a peculiar horseshoe-like shape. Contrary to the Sec14 crystal structure, the lipid-exchange loop is in a closed conformation, suggesting a mechanism for lipid exchange.

PubMed: 12429094
DOI: 10.1016/S0969-2126(02)00884-5

Experimental method

X-RAY DIFFRACTION (2.05 Å)