View source for 3al1


==DESIGNED PEPTIDE ALPHA-1, RACEMIC P1BAR FORM==
<StructureSection load='3al1' size='340' side='right'caption='[[3al1]], [[Resolution|resolution]] 0.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3al1]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3AL1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3AL1 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]] 0.75&#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>, <scene name='pdbligand=ETA:ETHANOLAMINE'>ETA</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</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=3al1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3al1 OCA], [https://pdbe.org/3al1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3al1 RCSB], [https://www.ebi.ac.uk/pdbsum/3al1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3al1 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
We report the 0.75 A crystal structure of a racemic mixture of the 12-residue designed peptide "Alpha-1" (Acetyl-ELLKKLLEELKG), the L-enantiomer of which is described in the accompanying paper. Equivalent solutions of the centrosymmetric bilayers were determined by two direct phasing programs in space groups P1 and P1bar. The unit cell contains two L-alpha-helices and two D-alpha-helices. The columnar-sheet bilayer motif seen in L-Alpha-1 is maintained in the D,L-Alpha-1 structure except that each sheet of head-to-tail helices is composed of one enantiomer and is related to its neighboring sheets by inversion symmetry. Comparison to the L-Alpha-1 structure provides further insight into peptide design. The high resolution and small asymmetric unit allowed building an intricate model (R = 13.1%, Rfree = 14.5%) that incorporates much of the discrete disorder of peptide and solvent. Ethanolamine and 2-methyl-2,4-pentanediol (MPD) molecules bind near helix termini. Rigid body analysis identifies sites of restricted displacements and torsions. Side-chain discrete disorder propagates into the backbone of one helix but not the other. Although no side chain in Alpha-1 is rigid, the environments in the crystal restrict some of them to no or only one active torsion.

Centrosymmetric bilayers in the 0.75 A resolution structure of a designed alpha-helical peptide, D,L-Alpha-1.,Patterson WR, Anderson DH, DeGrado WF, Cascio D, Eisenberg D Protein Sci. 1999 Jul;8(7):1410-22. PMID:10422829<ref>PMID:10422829</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3al1" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Anderson DH]]
[[Category: Cascio D]]
[[Category: Degrado WF]]
[[Category: Eisenberg D]]
[[Category: Patterson WR]]