1C44

STEROL CARRIER PROTEIN 2 (SCP2) FROM RABBIT

Summary for 1C44

• Entry DOI: 10.2210/pdb1c44/pdb
• Descriptor: PROTEIN (STEROL CARRIER PROTEIN 2) (2 entities in total)
• Functional Keywords: sterol carrier protein, non specific lipid transfer protein, fatty acid binding, fatty acyl coa binding, lipid binding protein
• Biological source: Oryctolagus cuniculus (rabbit)
• Total number of polymer chains: 1
• Total formula weight: 13211.38

Authors

Choinowski, T.,Hauser, H.,Piontek, K. (deposition date: 1999-07-02, release date: 2000-08-07, Last modification date: 2023-12-27)

Primary citation

Choinowski, T.,Hauser, H.,Piontek, K.
Structure of sterol carrier protein 2 at 1.8 A resolution reveals a hydrophobic tunnel suitable for lipid binding.
Biochemistry, 39:1897-1902, 2000

PubMed Abstract: Sterol carrier protein 2, also known as nonspecific lipid transfer protein is a ubiquitous, small, basic protein of 13 kDa found in animals. Its primary structure is highly conserved between different species, and it has been implicated in the intracellular transport of lipids and in a wide range of other in vitro functions related to sterol and fatty acid metabolism. Sterol carrier protein 2 deficiency in mice leads to elevated concentrations of phytanic acid in the serum and causes hepatocarcinogenesis. However, its actual physiological role is still unknown. Although sterol carrier protein 2 has been studied extensively in the past 20 years, very little is known concerning its three-dimensional structure. The crystal structure of rabbit sterol carrier protein 2, determined at 1.8 A resolution with the MIRAS method, shows a unique alpha/beta-fold. The core of this protein forms a five-stranded antiparallel beta-sheet flanked by five helices. A C-terminal segment (residues 114-123), together with part of the beta-sheet and four alpha-helices, form a hydrophobic tunnel providing the environment for apolar ligands such as fatty acids and fatty acyl-coenzyme As. Structurally well-characterized nonspecific lipid transfer proteins from plants have hydrophobic tunnel-like cavities, which were identified as the binding site for fatty acids and related apolar ligands. Despite the fact that plant nonspecific lipid transfer proteins are smaller proteins than sterol carrier protein 2, show no sequence homology to sterol carrier protein 2, and are structurally unrelated, the cavities of these two classes of proteins are very similar with respect to size, shape, and hydrophobicity, suggesting a common functional role.

PubMed: 10684638
DOI: 10.1021/bi992742e

Experimental method

X-RAY DIFFRACTION (1.8 Å)