The crystal structure of a wheat nonspecific lipid transfer protein (ns-LTP1) complexed with two molecules of phospholipid at 2.1 A resolution.
Nonspecific lipid transfer proteins (ns-LTP1) form a multigenic protein family in plants. In vitro they are able to bind all sort of lipids but their function, in vivo, remains speculative. A ns-LTP1 isolated from wheat seed was crystallized in the presence of lyso-myristoyl-phosphatidylcholine (LMPC). The structure was solved by molecular replacement and refined to 2.1 A resolution to an R-factor of 16.3% and a free R-factor of 21.3%. It reveals for the first time that the protein binds two LMPC molecules that are inserted head to tail in a hydrophobic cavity. A detailed study of the structure leads to the conclusion that there are two lipid-binding sites, one of which shows a higher affinity for the LMPC than the other. Comparison with other structures of lipid-bound ns-LTP1 suggests that the presence of two binding sites is a general feature of plant ns-LTP1.
Charvolin
D
D
Institut de Biologie Structural Jean-Pierre Ebel, CEA-CNRS, Nantes, France.
Douliez
J P
JP
Marion
D
D
Cohen-Addad
C
C
Pebay-Peyroula
E
E
D002352:Carrier Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D010713:Phosphatidylcholines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D010940:Plant Proteins; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D014908:Triticum / Q000737:chemistry*
D002352:Carrier Proteins; D010713:Phosphatidylcholines; D010743:Phospholipids; D010940:Plant Proteins; C072087:sterol carrier proteins