View source for 2lpi


==NMR structure of a monomeric mutant (A72R) of major ampullate spidroin 1 N-terminal domain==
<StructureSection load='2lpi' size='340' side='right'caption='[[2lpi]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2lpi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Euprosthenops_australis Euprosthenops australis]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2LPI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2LPI FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</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=2lpi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2lpi OCA], [https://pdbe.org/2lpi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2lpi RCSB], [https://www.ebi.ac.uk/pdbsum/2lpi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2lpi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q05H60_9ARAC Q05H60_9ARAC] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Formation of spider silk from its constituent proteins-spidroins-involves changes from soluble helical/coil conformations to insoluble beta-sheet aggregates. This conversion needs to be regulated to avoid precocious aggregation proximally in the silk gland while still allowing rapid silk assembly in the distal parts. Lowering of pH from about 7 to 6 is apparently important for silk formation. The spidroin N-terminal domain (NT) undergoes stable dimerization and structural changes in this pH region, but the underlying mechanisms are incompletely understood. Here, we determine the NMR and crystal structures of Euprosthenops australis NT mutated in the dimer interface (A72R). Also, the NMR structure of wild-type (wt) E. australis NT at pH7.2 and 300mM sodium chloride was determined. The wt NT and A72R structures are monomers and virtually identical, but they differ from the subunit structure of dimeric wt NT mainly by having a tryptophan (W10) buried between helix 1 and helix 3, while W10 is surface exposed in the dimer. Wedging of the W10 side chain in monomeric NT tilts helix 3 approximately 5-6A into a position that is incompatible with that of the observed dimer structure. The structural differences between monomeric and dimeric NT domains explain the tryptophan fluorescence patterns of NT at pH7 and pH6 and indicate that the biological function of NT depends on conversion between the two conformations.

pH-Dependent Dimerization of Spider Silk N-Terminal Domain Requires Relocation of a Wedged Tryptophan Side Chain.,Jaudzems K, Askarieh G, Landreh M, Nordling K, Hedhammar M, Jornvall H, Rising A, Knight SD, Johansson J J Mol Biol. 2012 Jun 15. PMID:22706024<ref>PMID:22706024</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2lpi" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Euprosthenops australis]]
[[Category: Large Structures]]
[[Category: Askarieh G]]
[[Category: Jaudzems K]]
[[Category: Johansson J]]
[[Category: Knight SD]]
[[Category: Landreh M]]
[[Category: Nordling K]]
[[Category: Rising A]]