PDBsum entry 1fk3

Lipid transport

PDB id: 1fk3

Contents

Protein chain

93 a.a. *

Ligands

PAM

FMT

Waters ×45

* Residue conservation analysis

PDB id:

1fk3

Name:

Lipid transport

Title:

Structural basis of non-specific lipid binding in maize lipid-transfer protein complexes with palmitoleic acid revealed by high-resolution x-ray crystallography

Structure:

Nonspecific lipid-transfer protein. Chain: a

Source:

Zea mays. Organism_taxid: 4577

Resolution:

1.80Å R-factor: 0.200 R-free: 0.236

Authors:

G.W.Han,J.Y.Lee,H.K.Song,D.H.Shin,S.W.Suh

Key ref:

G.W.Han et al. (2001). Structural basis of non-specific lipid binding in maize lipid-transfer protein complexes revealed by high-resolution X-ray crystallography. J Mol Biol, 308, 263-278. PubMed id: 11327766 DOI: 10.1006/jmbi.2001.4559

Date:

09-Aug-00 Release date: 06-Jun-01

Protein chain

P19656  (NLTP_MAIZE) -  Non-specific lipid-transfer protein from Zea mays

Seq: 120 a.a.

Struc: 93 a.a.

DOI no: 10.1006/jmbi.2001.4559

J Mol Biol 308:263-278 (2001)

PubMed id: 11327766

Structural basis of non-specific lipid binding in maize lipid-transfer protein complexes revealed by high-resolution X-ray crystallography.

G.W.Han, J.Y.Lee, H.K.Song, C.Chang, K.Min, J.Moon, D.H.Shin, M.L.Kopka, M.R.Sawaya, H.S.Yuan, T.D.Kim, J.Choe, D.Lim, H.J.Moon, S.W.Suh.

ABSTRACT

Non-specific lipid-transfer proteins (nsLTPs) are involved in the movement of phospholipids, glycolipids, fatty acids, and steroids between membranes. Several structures of plant nsLTPs have been determined both by X-ray crystallography and nuclear magnetic resonance. However, the detailed structural basis of the non-specific binding of hydrophobic ligands by nsLTPs is still poorly understood. In order to gain a better understanding of the structural basis of the non-specific binding of hydrophobic ligands by nsLTPs and to investigate the plasticity of the fatty acid binding cavity in nsLTPs, seven high-resolution (between 1.3 A and 1.9 A) crystal structures have been determined. These depict the nsLTP from maize seedlings in complex with an array of fatty acids.A detailed comparison of the structures of maize nsLTP in complex with various ligands reveals a new binding mode in an nsLTP-oleate complex which has not been seen before. Furthermore, in the caprate complex, the ligand binds to the protein cavity in two orientations with equal occupancy. The volume of the hydrophobic cavity in the nsLTP from maize shows some variation depending on the size of the bound ligands.The structural plasticity of the ligand binding cavity and the predominant involvement of non-specific van der Waals interactions with the hydrophobic tail of the ligands provide a structural explanation for the non-specificity of maize nsLTP. The hydrophobic cavity accommodates various ligands from C10 to C18. The C18:1 ricinoleate with its hydroxyl group hydrogen bonding to Ala68 possibly mimics cutin monomer binding which is of biological importance. Some of the myristate binding sites in human serum albumin resemble the maize nsLTP, implying the importance of a helical bundle in accommodating the non-specific binding of fatty acids.

Selected figure(s)

Figure 1.
Figure 1. (a) Stereo ribbon diagram of maize non-specific lipid-transfer protein complexed with oleate. The Figures were drawn with the MOLSCRIPT program.41 (b) Superposition of the backbone trace of eight nsLTP complexes. (c) Bound fatty acids showing structural comparisons between complexes. Colors used in (b) and (c): nsLTP:caprate (purple), nsLTP:laurate (red), nsLTP:myristate (dark red), nsLTP:palmitoleate (green), nsLTP-stearate (blue), nsLTP:oleate (dark green), nsLTP-linoleneate (yellow), and nsLTP-ricinoleate (dark blue).

Figure 6.
Figure 6. Comparisons of nsLTP:myristate with human serum albumin (HSA) in complex with myristate moieties. Insight II v97.5 (Molecular Simulations, Inc.) was used for the display. The three domains of HSA bind five myristate moieties; four are shown here, myr1, myr3, myr4, and myr5.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2001, 308, 263-278) copyright 2001.

Figures were selected by an automated process.