View source for 2evq


==Solution structure of HP7, a 12-residue beta hairpin==
<StructureSection load='2evq' size='340' side='right'caption='[[2evq]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2evq]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EVQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2EVQ 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=2evq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2evq OCA], [https://pdbe.org/2evq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2evq RCSB], [https://www.ebi.ac.uk/pdbsum/2evq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2evq ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Minimized beta hairpins have provided additional data on the geometric preferences of Trp interactions in TW-loop-WT motifs. This motif imparts significant fold stability to peptides as short as 8 residues. High-resolution NMR structures of a 16- (KKWTWNPATGKWTWQE, DeltaG(U)(298) &gt;or= +7 kJ/mol) and 12-residue (KTWNPATGKWTE, DeltaG(U)(298) = +5.05 kJ/mol) hairpin reveal a common turn geometry and edge-to-face (EtF) packing motif and a cation-pi interaction between Lys(1) and the Trp residue nearest the C-terminus. The magnitude of a CD exciton couplet (due to the two Trp residues) and the chemical shifts of a Trp Hepsilon3 site (shifted upfield by 2.4 ppm due to the EtF stacking geometry) provided near-identical measures of folding. CD melts of representative peptides with the -TW-loop-WT- motif provided the thermodynamic parameters for folding, which reflect enthalpically driven folding at laboratory temperatures with a small DeltaC(p) for unfolding (+420 J K(-)(1)/mol). In the case of Asx-Pro-Xaa-Thr-Gly-Xaa loops, mutations established that the two most important residues in this class of direction-reversing loops are Asx and Gly: mutation to alanine is destabilizing by about 6 and 2 kJ/mol, respectively. All indicators of structuring are retained in a minimized 8-residue construct (Ac-WNPATGKW-NH(2)) with the fold stability reduced to DeltaG(U)(278) = -0.7 kJ/mol. NMR and CD comparisons indicate that -TWXNGKWT- (X = S, I) sequences also form the same hairpin-stabilizing W/W interaction.

Minimization and optimization of designed beta-hairpin folds.,Andersen NH, Olsen KA, Fesinmeyer RM, Tan X, Hudson FM, Eidenschink LA, Farazi SR J Am Chem Soc. 2006 May 10;128(18):6101-10. PMID:16669679<ref>PMID:16669679</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 2evq" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Andersen NH]]
[[Category: Fesinmeyer RM]]
[[Category: Olsen KA]]