View source for 9hkg


==X-ray structure of Perm2, a circularly permuted mutant of the sweet protein MNEI==
<StructureSection load='9hkg' size='340' side='right'caption='[[9hkg]], [[Resolution|resolution]] 1.26&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9hkg]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Dioscoreophyllum_cumminsii Dioscoreophyllum cumminsii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9HKG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9HKG 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]] 1.26&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACY:ACETIC+ACID'>ACY</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=9hkg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9hkg OCA], [https://pdbe.org/9hkg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9hkg RCSB], [https://www.ebi.ac.uk/pdbsum/9hkg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9hkg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MONA_DIOCU MONA_DIOCU] Taste-modifying protein; intensely sweet-tasting protein.[https://www.uniprot.org/uniprot/MONB_DIOCU MONB_DIOCU] Taste-modifying protein; intensely sweet-tasting protein.
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== Publication Abstract from PubMed ==
Protein amyloid aggregates, once regarded solely as pathological hallmarks of human neurodegenerative diseases, have recently gained attention for their potential in biotechnological applications. Among others, MNEI and its variants, initially developed as single-chain derivatives of the sweet protein monellin, also serve as valuable models for studying protein fibrillary aggregation. In this work, we have characterized three circular permutated mutants of MNEI obtained joining the N- and C-termini of MNEI with linkers of different length and restoring the splitting of the polypeptide chain of native monellin. All proteins are well folded but have a different propensity to form oligomeric structures in solution and aggregation rates comparable to or faster than MNEI, as indicated by Thioflavin-T binding assays. Transmission Electron Microscopy (TEM) studies indicate that only Perm1, the mutant with the longest linker, forms fibrillar aggregates. X-ray structures of the mutants show that they crystallize as domain-swapped dimers. Molecular dynamics study highlights potential hot spots controlling the ordered aggregation process of Perm1. Our data support the idea that the formation of a domain-swapped dimer does not favour the formation of fibrillar aggregates and highlight circular permutation as a valuable tool to build nanostructured biomaterials.

Unravelling the amyloid aggregation mechanism of the sweet protein Monellin: Insights from circular permutated mutants.,Lucignano R, Bologna A, Gramazio S, Wang PH, Taxis C, Essen LO, Picone D, Spadaccini R Int J Biol Macromol. 2025 Mar 19;308(Pt 1):142239. doi: , 10.1016/j.ijbiomac.2025.142239. PMID:40118405<ref>PMID:40118405</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 9hkg" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Dioscoreophyllum cumminsii]]
[[Category: Large Structures]]
[[Category: Bologna A]]
[[Category: Essen L-O]]
[[Category: Spadaccini R]]
[[Category: Wang P-H]]