View source for 1cag


==CRYSTAL AND MOLECULAR STRUCTURE OF A COLLAGEN-LIKE PEPTIDE AT 1.9 ANGSTROM RESOLUTION==
<StructureSection load='1cag' size='340' side='right'caption='[[1cag]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1cag]] is a 3 chain structure. The April 2000 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Collagen''  by David S. Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2000_4 10.2210/rcsb_pdb/mom_2000_4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CAG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CAG 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]] 1.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACY:ACETIC+ACID'>ACY</scene>, <scene name='pdbligand=HYP:4-HYDROXYPROLINE'>HYP</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=1cag FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cag OCA], [https://pdbe.org/1cag PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1cag RCSB], [https://www.ebi.ac.uk/pdbsum/1cag PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1cag ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
The structure of a protein triple helix has been determined at 1.9 angstrom resolution by x-ray crystallographic studies of a collagen-like peptide containing a single substitution of the consensus sequence. This peptide adopts a triple-helical structure that confirms the basic features determined from fiber diffraction studies on collagen: supercoiling of polyproline II helices and interchain hydrogen bonding that follows the model II of Rich and Crick. In addition, the structure provides new information concerning the nature of this protein fold. Each triple helix is surrounded by a cylinder of hydration, with an extensive hydrogen bonding network between water molecules and peptide acceptor groups. Hydroxyproline residues have a critical role in this water network. The interaxial spacing of triple helices in the crystal is similar to that in collagen fibrils, and the water networks linking adjacent triple helices in the crystal structure are likely to be present in connective tissues. The breaking of the repeating (X-Y-Gly)n pattern by a Gly--&gt;Ala substitution results in a subtle alteration of the conformation, with a local untwisting of the triple helix. At the substitution site, direct interchain hydrogen bonds are replaced with interstitial water bridges between the peptide groups. Similar conformational changes may occur in Gly--&gt;X mutated collagens responsible for the diseases osteogenesis imperfecta, chondrodysplasias, and Ehlers-Danlos syndrome IV.

Crystal and molecular structure of a collagen-like peptide at 1.9 A resolution.,Bella J, Eaton M, Brodsky B, Berman HM Science. 1994 Oct 7;266(5182):75-81. PMID:7695699<ref>PMID:7695699</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1cag" style="background-color:#fffaf0;"></div>

==See Also==
*[[Collagen|Collagen]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Collagen]]
[[Category: Large Structures]]
[[Category: RCSB PDB Molecule of the Month]]
[[Category: Bella J]]
[[Category: Berman HM]]
[[Category: Brodsky B]]
[[Category: Eaton M]]