NMR structure of the sterol carrier protein-2: implications for the biological role.
The determination of the NMR structure of the sterol carrier protein-2 (SCP2), analysis of backbone (15)N spin relaxation parameters and NMR studies of nitroxide spin-labeled substrate binding are presented as a new basis for investigations of the mode of action of SCP2. The SCP2 fold is formed by a five-stranded beta-sheet and four alpha-helices. Fatty acid binding to a hydrophobic surface area formed by amino acid residues of the first and third helices, and the beta-sheet, which are all located in the polypeptide segment 8-102, was identified with the use of the spin-labeled substrate 16-doxylstearic acid. In the free protein, the lipid-binding site is covered by the C-terminal segment 105-123, suggesting that this polypeptide segment, which carries the peroxisomal targeting signal (PTS1), might be involved in the regulation of ligand binding.
García
F L
FL
Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule-Hönggerberg, Zürich, CH-8093, Switzerland.
Szyperski
T
T
Dyer
J H
JH
Choinowski
T
T
Seedorf
U
U
Hauser
H
H
Wüthrich
K
K
D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010940:Plant Proteins; D011487:Protein Conformation; D017510:Protein Folding; D011817:Rabbits
D002352:Carrier Proteins; D010940:Plant Proteins; C072087:sterol carrier proteins