View source for 1xd6


==Crystal structures of novel monomeric monocot mannose-binding lectins from Gastrodia elata==
<StructureSection load='1xd6' size='340' side='right'caption='[[1xd6]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1xd6]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Gastrodia_elata Gastrodia elata]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XD6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XD6 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1xd6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xd6 OCA], [https://pdbe.org/1xd6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xd6 RCSB], [https://www.ebi.ac.uk/pdbsum/1xd6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xd6 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q1M0Y9_9ASPA Q1M0Y9_9ASPA] 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/xd/1xd6_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1xd6 ConSurf].
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== Publication Abstract from PubMed ==
Two isoforms of an antifungal protein, gastrodianin, were isolated from two subspecies of the orchid Gastrodia elata, belonging to the protein superfamily of monocot mannose-specific lectins. In the context that all available structures in this superfamily are oligomers so far, the crystal structures of the orchid lectins, both at 2.0 A, revealed a novel monomeric structure. It resulted from the rearrangement of the C-terminal peptide inclusive of the 12th beta-strand, which changes from the "C-terminal exchange" into a "C-terminal self-assembly" mode. Thus, the overall tertiary scaffold is stabilized with an intramolecular beta-sheet instead of the hybrid observed on subunit/subunit interface in all known homologous dimeric or tetrameric lectins. In contrast to the constrained extended conformation with a cis peptide bond between residues 98 and 99 commonly occurring in oligomers, a beta-hairpin forms from position 97 to 101 with a normal trans peptide bond at the corresponding site in gastrodianin, which determines the topology of the C-terminal peptide and thereby its unique fold pattern. Sequence and structure comparison shows that residue replacement and insertion at the position where the beta-hairpin occurs in association with cis-trans inter-conversion of the specific peptide bond (97-98) are possibly responsible for such a radical structure switch between monomers and oligomers. Moreover, this seems to be a common melody controlling the quaternary states among bulb lectins through studies on sequence alignment. The observations revealed a structural mechanism by which the quaternary organization of monocot mannose binding lectins could be governed. The mutation experiment performed on maltose-binding protein-gastrodianin fusion protein followed by a few biochemical detections provides direct evidence to support this conclusion. Potential carbohydrate recognition sites and biological implications of the orchid lectin based on its monomeric state are also discussed in this paper.

Structural mechanism governing the quaternary organization of monocot mannose-binding lectin revealed by the novel monomeric structure of an orchid lectin.,Liu W, Yang N, Ding J, Huang RH, Hu Z, Wang DC J Biol Chem. 2005 Apr 15;280(15):14865-76. Epub 2005 Jan 13. PMID:15649901<ref>PMID:15649901</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Gastrodia elata]]
[[Category: Large Structures]]
[[Category: Hu Z]]
[[Category: Huang RH]]
[[Category: Liu W]]
[[Category: Wang DC]]
[[Category: Wang M]]
[[Category: Yang N]]