View source for 7t2y


==X-ray structure of a designed cold unfolding four helix bundle==
<StructureSection load='7t2y' size='340' side='right'caption='[[7t2y]], [[Resolution|resolution]] 1.34&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7t2y]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7T2Y OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7T2Y 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]] 1.34&#8491;</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=7t2y FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7t2y OCA], [https://pdbe.org/7t2y PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7t2y RCSB], [https://www.ebi.ac.uk/pdbsum/7t2y PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7t2y ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Understanding protein folding is crucial for protein sciences. The conformational spaces and energy landscapes of cold (unfolded) protein states, as well as the associated transitions, are hardly explored. Furthermore, it is not known how structure relates to the cooperativity of cold transitions, if cold and heat unfolded states are thermodynamically similar, and if cold states play important roles for protein function. We created the cold unfolding 4-helix bundle DCUB1 with a de novo designed bipartite hydrophilic/hydrophobic core featuring a hydrogen bond network which extends across the bundle in order to study the relative importance of hydrophobic versus hydrophilic protein-water interactions for cold unfolding. Structural and thermodynamic characterization resulted in the discovery of a complex energy landscape for cold transitions, while the heat unfolded state is a random coil. Below approximately 0 degrees C, the core of DCUB1 disintegrates in a largely cooperative manner, while a near-native helical content is retained. The resulting cold core-unfolded state is compact and features extensive internal dynamics. Below -5 degrees C, two additional cold transitions are seen, that is, (i) the formation of a water-mediated, compact, and highly dynamic dimer, and (ii) the onset of cold helix unfolding decoupled from cold core unfolding. Our results suggest that cold unfolding is initiated by the intrusion of water into the hydrophilic core network and that cooperativity can be tuned by varying the number of core hydrogen bond networks. Protein design has proven to be invaluable to explore the energy landscapes of cold states and to robustly test related theories.

From Protein Design to the Energy Landscape of a Cold Unfolding Protein.,Pulavarti SVSRK, Maguire JB, Yuen S, Harrison JS, Griffin J, Premkumar L, Esposito EA, Makhatadze GI, Garcia AE, Weiss TM, Snell EH, Kuhlman B, Szyperski T J Phys Chem B. 2022 Feb 17;126(6):1212-1231. doi: 10.1021/acs.jpcb.1c10750. Epub , 2022 Feb 7. PMID:35128921<ref>PMID:35128921</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 7t2y" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Harrison JS]]
[[Category: Kuhlman B]]
[[Category: Maguire J]]
[[Category: Premkumar L]]
[[Category: Pulavarti S]]
[[Category: Szyperski T]]
[[Category: Yuen S]]