1LN1

Crystal Structure of Human Phosphatidylcholine Transfer Protein in Complex with Dilinoleoylphosphatidylcholine

Summary for 1LN1

• Entry DOI: 10.2210/pdb1ln1/pdb
• Related: 1LN2 1LN3
• Descriptor: Phosphatidylcholine transfer protein, 1,2-DILINOLEOYL-SN-GLYCERO-3-PHOSPHOCHOLINE (3 entities in total)
• Functional Keywords: start domain, lipid binding protein
• Biological source: Homo sapiens (human)
• Cellular location: Cytoplasm : Q9UKL6
• Total number of polymer chains: 1
• Total formula weight: 25653.38

Authors

Roderick, S.L.,Chan, W.W.,Agate, D.S.,Olsen, L.R.,Vetting, M.W.,Rajashankar, K.R.,Cohen, D.E. (deposition date: 2002-05-02, release date: 2002-06-26, Last modification date: 2024-11-20)

Primary citation

Roderick, S.L.,Chan, W.W.,Agate, D.S.,Olsen, L.R.,Vetting, M.W.,Rajashankar, K.R.,Cohen, D.E.
Structure of human phosphatidylcholine transfer protein in complex with its ligand.
Nat.Struct.Biol., 9:507-511, 2002

PubMed 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.

PubMed: 12055623

Experimental method

X-RAY DIFFRACTION (2.4 Å)