1t12
From Proteopedia
Solution Structure of a new LTP1
Structural highlights
FunctionNLTP1_TOBAC Plant non-specific lipid-transfer proteins transfer phospholipids as well as galactolipids across membranes. Binds cis-unsaturated fatty acids and jasmonic acid with a higher affinity than linear chain fatty acids. Formation of the complex with jasmonic acid results in a conformational change facilitating the LPT1 binding on the elicitin plasma membrane receptor that is known to be involved in plant defense induction. May also play a role in wax or cutin deposition in the cell walls of expanding epidermal cells and certain secretory tissues.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPlant lipid transfer proteins are small soluble extracellular proteins that are able to bind and transfer a variety of lipids in vitro. Recently, it has been proposed that lipid transfer proteins may play a key role in plant defence mechanisms, especially during the induction of systemic acquired resistance. However, very little is known about the proteins expressed in developing plants and tissues, since almost all the biophysical and structural data available to date on lipid transfer proteins originate from proteins present in storage tissues of monocot cereal seeds. In this paper, we report the structural and functional characteristics of a lipid transfer protein (named LTP1_1) constitutively expressed in young aerial organs of Nicotiana tabacum (common tobacco). The unlabelled and uniformly labelled proteins were produced in the yeast Pichia pastoris, and we determined the three-dimensional (3D) structure of LTP1_1 using nuclear magnetic resonance (NMR) spectroscopy and molecular modeling techniques. The global fold of LTP1_1 is very close to the previously published structures of LTP1 extracted from cereal seeds, including an internal cavity. However, the chemical shift variations of several NMR signals upon lipid binding show that tobacco LTP1_1 is able to bind only one LysoMyristoylPhosphatidylCholine (LMPC), while wheat and maize LTPs can bind either one or two. Titration experiments using intrinsic tyrosine fluorescence confirm this result not only with LMPC but also with two fatty acids. These differences can be explained by the presence in tobacco LTP1_1 of a hydrophobic cluster closing the second possible access to the protein cavity. This result suggests that LTP1 lipid binding properties could be modulated by subtle changes in a conserved global structure. The biological significance of this finding is discussed in the light of the signalling properties of the tobacco LTP1_1-jasmonate complex described elsewhere. Solution structure of a tobacco lipid transfer protein exhibiting new biophysical and biological features.,Da Silva P, Landon C, Industri B, Marais A, Marion D, Ponchet M, Vovelle F Proteins. 2005 May 1;59(2):356-67. PMID:15726627[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||
