We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Structure of human phosphatidylcholine transfer protein in complex with its ligand.
- Authors
Roderick, Steven L; Chan, Wayne W; Agate, Diana S; Olsen, Laurence R; Vetting, Matt W; Rajashankar, K R; Cohen, David E
- Abstract
Phosphatidylcholines (PtdChos) comprise the most common phospholipid class in eukaryotic cells. In mammalian cells, these insoluble molecules are transferred between membranes by a highly specific phosphatidylcholine transfer protein (PC-TP) belonging to the steroidogenic acute regulatory protein related transfer (START) domain superfamily of hydrophobic ligand-binding proteins. The crystal structures of human PC-TP in complex with dilinoleoyl-PtdCho or palmitoyl-linoleoyl-PtdCho reveal that a single well-ordered PtdCho molecule occupies a centrally located tunnel. The positively charged choline headgroup of the lipid engages in cation-pi interactions within a cage formed by the faces of three aromatic residues. These binding determinants and those for the phosphoryl group may be exposed to the lipid headgroup at the membrane-water interface by a conformational change involving the amphipathic C-terminal helix and an Omega-loop. The structures presented here provide a basis for rationalizing the specificity of PC-TP for PtdCho and may identify common features used by START proteins to bind their hydrophobic ligands.
- Publication
Nature structural biology, 2002, Vol 9, Issue 7, p507
- ISSN
1072-8368
- Publication type
Journal Article
- DOI
10.1038/nsb812