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| - | [[Image:1c58.gif|left|200px]] | |
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| - | {{Structure
| + | ==CRYSTAL STRUCTURE OF CYCLOAMYLOSE 26== |
| - | |PDB= 1c58 |SIZE=350|CAPTION= <scene name='initialview01'>1c58</scene>, resolution 0.99Å
| + | <StructureSection load='1c58' size='340' side='right'caption='[[1c58]], [[Resolution|resolution]] 0.99Å' scene=''> |
| - | |SITE=
| + | == Structural highlights == |
| - | |LIGAND=
| + | <table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C58 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1C58 FirstGlance]. <br> |
| - | |ACTIVITY=
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-RAY DIFFRACTION, [[Resolution|Resolution]] 0.99Å</td></tr> |
| - | |GENE=
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</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=1c58 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1c58 OCA], [https://pdbe.org/1c58 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1c58 RCSB], [https://www.ebi.ac.uk/pdbsum/1c58 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1c58 ProSAT]</span></td></tr> |
| - | | + | </table> |
| - | '''CRYSTAL STRUCTURE OF CYCLOAMYLOSE 26''' | + | __TOC__ |
| - | | + | </StructureSection> |
| - | | + | [[Category: Large Structures]] |
| - | ==Overview== | + | [[Category: Gessler, K]] |
| - | The amylose fraction of starch occurs in double-helical A- and B-amyloses and the single-helical V-amylose. The latter contains a channel-like central cavity that is able to include molecules, "iodine's blue" being the best-known representative. Molecular models of these amylose forms have been deduced by solid state 13C cross-polarization/magic angle spinning NMR and by x-ray fiber and electron diffraction combined with computer-aided modeling. They remain uncertain, however, as no structure at atomic resolution is available. We report here the crystal structure of a hydrated cycloamylose containing 26 glucose residues (cyclomaltohexaicosaose, CA26), which has been determined by real/reciprocal space recycling starting from randomly positioned atoms or from an oriented diglucose fragment. This structure provides conclusive evidence for the structure of V-amylose, as the macrocycle of CA26 is folded into two short left-handed V-amylose helices in antiparallel arrangement and related by twofold rotational pseudosymmetry. In the V-helices, all glucose residues are in syn orientation, forming systematic interglucose O(3)n...O(2)(n+l) and O(6)n...O(2)(n+6)/O(3)(n+6) hydrogen bonds; the central cavities of the V-helices are filled by disordered water molecules. The folding of the CA26 macrocycle is characterized by typical "band-flips" in which diametrically opposed glucose residues are in anti rather than in the common syn orientation, this conformation being stabilized by interglucose three-center hydrogen bonds with O(3)n as donor and O(5)(n+l), O(6)(n+l) as acceptors. The structure of CA26 permitted construction of an idealized V-amylose helix, and the band-flip motif explains why V-amylose crystallizes readily and may be packed tightly in seeds.
| + | [[Category: Nimz, O]] |
| - | | + | [[Category: Saenger, W]] |
| - | ==About this Structure== | + | [[Category: Carbohydrate]] |
| - | 1C58 is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C58 OCA].
| + | [[Category: Cycloamylose]] |
| - | | + | |
| - | ==Reference==
| + | |
| - | V-Amylose at atomic resolution: X-ray structure of a cycloamylose with 26 glucose residues (cyclomaltohexaicosaose)., Gessler K, Uson I, Takaha T, Krauss N, Smith SM, Okada S, Sheldrick GM, Saenger W, Proc Natl Acad Sci U S A. 1999 Apr 13;96(8):4246-51. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10200247 10200247]
| + | |
| - | [[Category: Protein complex]] | + | |
| - | [[Category: Gessler, K.]] | + | |
| - | [[Category: Nimz, O.]] | + | |
| - | [[Category: Saenger, W.]] | + | |
| - | [[Category: cycloamylose]] | + | |
| - | | + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 10:19:57 2008''
| + | |
