2r2v: Difference between revisions
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==Sequence Determinants of the Topology of the Lac Repressor Tetrameric Coiled Coil== | |||
<StructureSection load='2r2v' size='340' side='right'caption='[[2r2v]], [[Resolution|resolution]] 1.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2r2v]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2R2V OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2R2V 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]] 1.9Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=2r2v FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2r2v OCA], [https://pdbe.org/2r2v PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2r2v RCSB], [https://www.ebi.ac.uk/pdbsum/2r2v PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2r2v ProSAT]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Predictive understanding of how the folded, functional shape of a native protein is encoded in the linear sequence of its amino acid residues remains an unsolved challenge in modern structural biology. Antiparallel four-stranded coiled coils are relatively simple protein structures that embody a heptad sequence repeat and rich diversity for tertiary packing of alpha-helices. To explore specific sequence determinants of the lac repressor coiled-coil tetramerization domain, we have engineered a set of buried nonpolar side chains at the a-, d-, and e-positions into the hydrophobic interior of the dimeric GCN4 leucine zipper. Circular dichroism and equilibrium ultracentrifugation studies show that this core variant (GCN4-pAeLV) forms a stable tetrameric structure with a reversible and highly cooperative thermal unfolding transition. The X-ray crystal structure at 1.9 A reveals that GCN4-pAeLV is an antiparallel four-stranded coiled coil of the lac repressor type in which the a, d, and e side chains associate by means of combined knobs-against-knobs and knobs-into-holes packing with a characteristic interhelical offset of 0.25 heptad. Comparison of the side chain shape and packing in the antiparallel tetramers shows that the burial of alanine residues at the e positions between the neighboring helices of GCN4-pAeLV dictates both the antiparallel orientation and helix offset. This study fills in a gap in our knowledge of the determinants of structural specificity in antiparallel coiled coils and improves our understanding of how specific side chain packing forms the teritiary structure of a functional protein. | |||
Conformational specificity of the lac repressor coiled-coil tetramerization domain.,Liu J, Zheng Q, Deng Y, Li Q, Kallenbach NR, Lu M Biochemistry. 2007 Dec 25;46(51):14951-9. Epub 2007 Dec 4. PMID:18052214<ref>PMID:18052214</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2r2v" style="background-color:#fffaf0;"></div> | |||
== | ==See Also== | ||
*[[Gcn4 3D Structures|Gcn4 3D Structures]] | |||
*[[Gnc4 3D Structures|Gnc4 3D Structures]] | |||
*[[Lac repressor|Lac repressor]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Saccharomyces cerevisiae]] | [[Category: Saccharomyces cerevisiae]] | ||
[[Category: Liu J]] | |||
[[Category: Liu | [[Category: Lu M]] | ||
[[Category: Lu | |||