1jtb
From Proteopedia
(New page: 200px<br /><applet load="1jtb" size="450" color="white" frame="true" align="right" spinBox="true" caption="1jtb" /> '''LIPID TRANSFER PROTEIN COMPLEXED WITH PALMIT...) |
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| - | [[Image:1jtb.gif|left|200px]]<br /><applet load="1jtb" size=" | + | [[Image:1jtb.gif|left|200px]]<br /><applet load="1jtb" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1jtb" /> | caption="1jtb" /> | ||
'''LIPID TRANSFER PROTEIN COMPLEXED WITH PALMITOYL COENZYME A, NMR, 16 STRUCTURES'''<br /> | '''LIPID TRANSFER PROTEIN COMPLEXED WITH PALMITOYL COENZYME A, NMR, 16 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND:. Plant nonspecific lipid-transfer proteins (nsLTPs) bind a | + | BACKGROUND:. Plant nonspecific lipid-transfer proteins (nsLTPs) bind a variety of very different lipids in vitro, including phospholipids, glycolipids, fatty acids and acyl coenzyme As. In this study we have determined the structure of a nsLTP complexed with palmitoyl coenzyme A (PCoA) in order to further our understanding of the structural mechanism of the broad specificity of these proteins and its relation to the function of nsLTPs in vivo. RESULTS:. 1H and 13C nuclear magnetic resonance spectroscopy (NMR) have been used to study the complex between a nsLTP isolated from barley seeds (bLTP) and the ligand PCoA. The resonances of 97% of the 1H atoms were assigned for the complexed bLTP and nearly all of the resonances were assigned in the bound PCoA ligand. The palmitoyl chain of the ligand was uniformly 13C-labelled allowing the two ends of the hydrocarbon chain to be assigned. The comparison of a subset of 20 calculated structures to an average structure showed root mean square deviations of 1.89 +/- 0.19 for all C, N, O, P and S atoms of the entire complex and of 0.57 +/- 0.09 for the peptide backbone atoms of the four alpha helices of the complexed bLTP. The four-helix topology of the uncomplexed bLTP is maintained in the complexed form of the protein. The bLTP only binds the hydrophobic parts of PCoA with the rest of the ligand remaining exposed to the solvent. The palmitoyl chain moiety of the ligand is placed in the interior of the protein and bent in a U-shape. This part of the ligand is completely buried within a hydrophobic pocket of the protein. CONCLUSIONS:. A comparison of the structures of bLTP in the free and bound forms suggests that bLTP can accommodate long olefinic ligands by expansion of the hydrophobic binding site. This expansion is achieved by a bend of one helix, HA, and by conformational changes in both the C terminus and helix HC. This mode of binding is different from that seen in the structure of maize nsLTP in complex with palmitic acid, where binding of the ligand is not associated with structural changes. |
==About this Structure== | ==About this Structure== | ||
| - | 1JTB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare] with COA and PLM as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1JTB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare] with <scene name='pdbligand=COA:'>COA</scene> and <scene name='pdbligand=PLM:'>PLM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JTB OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Hordeum vulgare]] | [[Category: Hordeum vulgare]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Bech, L | + | [[Category: Bech, L M.]] |
| - | [[Category: Kragelund, B | + | [[Category: Kragelund, B B.]] |
| - | [[Category: Lerche, M | + | [[Category: Lerche, M H.]] |
| - | [[Category: Poulsen, F | + | [[Category: Poulsen, F M.]] |
[[Category: COA]] | [[Category: COA]] | ||
[[Category: PLM]] | [[Category: PLM]] | ||
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[[Category: lipid transport]] | [[Category: lipid transport]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:26:29 2008'' |
Revision as of 11:26, 21 February 2008
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LIPID TRANSFER PROTEIN COMPLEXED WITH PALMITOYL COENZYME A, NMR, 16 STRUCTURES
Overview
BACKGROUND:. Plant nonspecific lipid-transfer proteins (nsLTPs) bind a variety of very different lipids in vitro, including phospholipids, glycolipids, fatty acids and acyl coenzyme As. In this study we have determined the structure of a nsLTP complexed with palmitoyl coenzyme A (PCoA) in order to further our understanding of the structural mechanism of the broad specificity of these proteins and its relation to the function of nsLTPs in vivo. RESULTS:. 1H and 13C nuclear magnetic resonance spectroscopy (NMR) have been used to study the complex between a nsLTP isolated from barley seeds (bLTP) and the ligand PCoA. The resonances of 97% of the 1H atoms were assigned for the complexed bLTP and nearly all of the resonances were assigned in the bound PCoA ligand. The palmitoyl chain of the ligand was uniformly 13C-labelled allowing the two ends of the hydrocarbon chain to be assigned. The comparison of a subset of 20 calculated structures to an average structure showed root mean square deviations of 1.89 +/- 0.19 for all C, N, O, P and S atoms of the entire complex and of 0.57 +/- 0.09 for the peptide backbone atoms of the four alpha helices of the complexed bLTP. The four-helix topology of the uncomplexed bLTP is maintained in the complexed form of the protein. The bLTP only binds the hydrophobic parts of PCoA with the rest of the ligand remaining exposed to the solvent. The palmitoyl chain moiety of the ligand is placed in the interior of the protein and bent in a U-shape. This part of the ligand is completely buried within a hydrophobic pocket of the protein. CONCLUSIONS:. A comparison of the structures of bLTP in the free and bound forms suggests that bLTP can accommodate long olefinic ligands by expansion of the hydrophobic binding site. This expansion is achieved by a bend of one helix, HA, and by conformational changes in both the C terminus and helix HC. This mode of binding is different from that seen in the structure of maize nsLTP in complex with palmitic acid, where binding of the ligand is not associated with structural changes.
About this Structure
1JTB is a Single protein structure of sequence from Hordeum vulgare with and as ligands. Full crystallographic information is available from OCA.
Reference
Barley lipid-transfer protein complexed with palmitoyl CoA: the structure reveals a hydrophobic binding site that can expand to fit both large and small lipid-like ligands., Lerche MH, Kragelund BB, Bech LM, Poulsen FM, Structure. 1997 Feb 15;5(2):291-306. PMID:9032083
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