View source for 3vhf


==plant thaumatin I at pH 8.0==
<StructureSection load='3vhf' size='340' side='right'caption='[[3vhf]], [[Resolution|resolution]] 1.39&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3vhf]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Thaumatococcus_daniellii Thaumatococcus daniellii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3VHF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3VHF 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]] 1.39&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</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=3vhf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3vhf OCA], [https://pdbe.org/3vhf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3vhf RCSB], [https://www.ebi.ac.uk/pdbsum/3vhf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3vhf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/THM1_THADA THM1_THADA] Taste-modifying protein; intensely sweet-tasting. It is 100000 times sweeter than sucrose on a molar basis.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Thaumatin, an intensely sweet-tasting plant protein, elicits a sweet taste at 50 nM. Although the sweetness remains when thaumatin is heated at 80 degrees C for 4h under acid conditions, it rapidly declines when heating at a pH above 6.5. To clarify the structural difference at high pH, the atomic structure of a recombinant thaumatin I at pH 8.0 was determined at a resolution of 1.0A. Comparison to the crystal structure of thaumatin at pH 7.3 and 7.0 revealed the root-mean square deviation value of a Calpha atom to be substantially greater in the large disulfide-rich region of domain II, especially residues 154-164, suggesting that a loop region in domain II to be affected by solvent conditions. Furthermore, B-factors of Lys137, Lys163, and Lys187 were significantly affected by pH change, suggesting that a striking increase in the mobility of these lysine residues, which could facilitate a reaction with a free sulfhydryl residue produced via the beta-elimination of disulfide bonds by heating at a pH above 7.0. The increase in mobility of lysine residues as well as a loop region in domain II might play an important role in the heat-induced aggregation of thaumatin above pH 7.0.

Atomic structure of the sweet-tasting protein thaumatin I at pH 8.0 reveals the large disulfide-rich region in domain II to be sensitive to a pH change.,Masuda T, Ohta K, Mikami B, Kitabatake N, Tani F Biochem Biophys Res Commun. 2012 Mar 2;419(1):72-6. Epub 2012 Feb 3. PMID:22326916<ref>PMID:22326916</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3vhf" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thaumatococcus daniellii]]
[[Category: Kitabatake N]]
[[Category: Masuda T]]
[[Category: Mikami B]]
[[Category: Tani F]]