View source for 4kvt


==Crystal structure of a 6-helix coiled coil CC-Hex-L24C==
<StructureSection load='4kvt' size='340' side='right'caption='[[4kvt]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4kvt]] is a 6 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4KVT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4KVT 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]] 1.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</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=4kvt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4kvt OCA], [https://pdbe.org/4kvt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4kvt RCSB], [https://www.ebi.ac.uk/pdbsum/4kvt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4kvt ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Ab initio design of enzymes requires precise and predictable positioning of reactive functional groups within accessible and controlled environments of de novo protein scaffolds. Here we show that multiple thiol moieties can be placed within a central channel, with approximate dimensions 6 x 42 A, of a de novo, six-helix peptide assembly (CC-Hex). Layers of six cysteine residues are introduced at two different sites approximately 6 (the "L24C" mutant) and approximately 17 A (L17C) from the C-terminal opening of the channel. X-ray crystal structures confirm the mutant structures as hexamers with internal free thiol, rather than disulfide-linked cysteine residues. Both mutants are hexa-alkylated upon addition of iodoacetamide, demonstrating accessibility and full reactivity of the thiol groups. Comparison of the alkylation and unfolding rates of the hexamers indicates that access is directly through the channel and not via dissociation and unfolding of the assembly. Moreover, neither mutant reacts with iodoacetic acid, demonstrating selectivity of the largely hydrophobic channel. These studies show that it is possible to engineer reactive side chains with both precision and control into a de novo scaffold to produce protein-like structures with chemoselective reactivity.

Accessibility, Reactivity, and Selectivity of Side Chains within a Channel of de Novo Peptide Assembly.,Burton AJ, Thomas F, Agnew C, Hudson KL, Halford SE, Brady RL, Woolfson DN J Am Chem Soc. 2013 Aug 13. PMID:23924058<ref>PMID:23924058</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4kvt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Agnew C]]
[[Category: Brady RL]]
[[Category: Burton AJ]]
[[Category: Woolfson DN]]