4qkr

<table><tr><td colspan='2'>[[4qkr]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Synthetic_construct_sequences Synthetic construct sequences]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4QKR OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4QKR FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=IMD:IMIDAZOLE'>IMD</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4d8h|4d8h]], [[4qks|4qks]]</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4qkr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qkr OCA], [http://pdbe.org/4qkr PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4qkr RCSB], [http://www.ebi.ac.uk/pdbsum/4qkr PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4qkr ProSAT]</span></td></tr>

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

The halophile environment has a number of compelling aspects with regard to the origin of structured polypeptides (i.e., proteogenesis) and, instead of a curious niche that living systems adapted into, the halophile environment is emerging as a candidate "cradle" for proteogenesis. In this viewpoint, a subsequent halophile-to-mesophile transition was a key step in early evolution. Several lines of evidence indicate that aromatic amino acids were a late addition to the codon table and not part of the original "prebiotic" set comprising the earliest polypeptides. We test the hypothesis that the availability of aromatic amino acids could facilitate a halophile-to-mesophile transition by hydrophobic core-packing enhancement. The effects of aromatic amino acid substitutions were evaluated in the core of a "primitive" designed protein enriched for the 10 prebiotic amino acids (A,D,E,G,I,L,P,S,T,V)-having an exclusively prebiotic core and requiring halophilic conditions for folding. The results indicate that a single aromatic amino acid substitution is capable of eliminating the requirement of halophile conditions for folding of a "primitive" polypeptide. Thus, the availability of aromatic amino acids could have facilitated a critical halophile-to-mesophile protein folding adaptation-identifying a selective advantage for the incorporation of aromatic amino acids into the codon table.

A single aromatic core mutation converts a designed "primitive" protein from halophile to mesophile folding.,Longo LM, Tenorio CA, Kumru OS, Middaugh CR, Blaber M Protein Sci. 2015 Jan;24(1):27-37. doi: 10.1002/pro.2580. Epub 2014 Oct 25. PMID:25297559<ref>PMID:25297559</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 4qkr" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Synthetic construct sequences]]

[[Category: Blaber, M]]

[[Category: Longo, L M]]

[[Category: Tenorio, C A]]

[[Category: Simplified protein design]]