Structural evidence for adaptive ligand binding of glycolipid transfer protein.
Glycolipids participate in many important cellular processes and they are bound and transferred with high specificity by glycolipid transfer protein (GLTP). We have solved three different X-ray structures of bovine GLTP at 1.4 angstroms, 1.6 angstroms and 1.8 angstroms resolution, all with a bound fatty acid or glycolipid. The 1.4 angstroms structure resembles the recently characterized apo-form of the human GLTP but the other two structures represent an intermediate conformation of the apo-GLTPs and the human lactosylceramide-bound GLTP structure. These novel structures give insight into the mechanism of lipid binding and how GLTP may conformationally adapt to different lipids. Furthermore, based on the structural comparison of the GLTP structures and the three-dimensional models of the related Podospora anserina HET-C2 and Arabidopsis thaliana accelerated cell death protein, ACD11, we give structural explanations for their specific lipid binding properties.
Airenne
Tomi T
TT
Department of Biochemistry and Pharmacy, Abo Akademi University, Tykistökatu 6A, FIN-20520 Turku, Finland.
Kidron
Heidi
H
Nymalm
Yvonne
Y
Nylund
Matts
M
West
Gun
G
Mattjus
Peter
P
Salminen
Tiina A
TA
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D002417:Cattle; D018360:Crystallography, X-Ray; D004220:Disulfides / Q000737:chemistry; D006017:Glycolipids / Q000378:metabolism; D008024:Ligands; D008969:Molecular Sequence Data; D016415:Sequence Alignment
D002352:Carrier Proteins; D004220:Disulfides; C511922:GLTP protein, human; D006017:Glycolipids; D008024:Ligands; C030363:lipid transfer protein