The crystal structure of a wheat nonspecific lipid transfer protein (ns-LTP1) complexed with two molecules of phospholipid at 2.1 A resolution

Eur J Biochem. 1999 Sep;264(2):562-8. doi: 10.1046/j.1432-1327.1999.00667.x.

Abstract

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.

MeSH terms

  • Carrier Proteins / chemistry*
  • Crystallography, X-Ray
  • Models, Molecular
  • Phosphatidylcholines / chemistry
  • Phospholipids / chemistry*
  • Plant Proteins*
  • Protein Binding
  • Protein Conformation
  • Protein Structure, Secondary
  • Triticum / chemistry*

Substances

  • Carrier Proteins
  • Phosphatidylcholines
  • Phospholipids
  • Plant Proteins
  • sterol carrier proteins

Associated data

  • PDB/1BWO
  • PDB/1BWOSD