1c44
|
STEROL CARRIER PROTEIN 2 (SCP2) FROM RABBIT
OverviewOverview
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.
About this StructureAbout this Structure
1C44 is a Single protein structure of sequence from Oryctolagus cuniculus. Full crystallographic information is available from OCA.
ReferenceReference
Structure of sterol carrier protein 2 at 1.8 A resolution reveals a hydrophobic tunnel suitable for lipid binding., Choinowski T, Hauser H, Piontek K, Biochemistry. 2000 Feb 29;39(8):1897-902. PMID:10684638
Page seeded by OCA on Tue Nov 20 12:08:36 2007