View source for 1fqd

==CRYSTAL STRUCTURE OF MALTOTETRAITOL BOUND TO CLOSED-FORM MALTODEXTRIN BINDING PROTEIN==
<StructureSection load='1fqd' size='340' side='right' caption='[[1fqd]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1fqd]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FQD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1FQD FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=GLO:D-GLUCOSE+IN+LINEAR+FORM'>GLO</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1omp|1omp]], [[1anf|1anf]]</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=1fqd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1fqd OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1fqd RCSB], [http://www.ebi.ac.uk/pdbsum/1fqd PDBsum]</span></td></tr>
</table>
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/fq/1fqd_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
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== Publication Abstract from PubMed ==
The structure of the maltodextrin or maltose-binding protein, an initial receptor for bacterial ABC-type active transport and chemotaxis, consists of two globular domains that are separated by a groove wherein the ligand is bound and enclosed by an inter-domain rotation. Here, we report the determination of the crystal structures of the protein complexed with reduced maltooligosaccharides (maltotriitol and maltotetraitol) in both the "closed" and "open" forms. Although these modified sugars bind to the receptor, they are not transported by the wild-type transporter. In the closed structures, the reduced sugars are buried in the groove and bound by both domains, one domain mainly by hydrogen-bonding interactions and the other domain primarily by non-polar interactions with aromatic side-chains. In the open structures, which abrogate both cellular activities of active transport and chemotaxis because of the large separation between the two domains, the sugars are bound almost exclusively to the domain rich in aromatic residues. The binding site for the open chain glucitol residue extends to a subsite that is distinct from those for the glucose residues that were uncovered in prior structural studies of the binding of active linear maltooligosaccharides. Occupation of this subsite may also account for the inability of the reduced oligosaccharides to be transported. The structures reported here, combined with those previously determined for several other complexes with active oligosaccharides in the closed form and with cyclodextrin in the open form, revealed at least four distinct modes of ligand binding but with only one being functionally active. This versatility reflects the flexibility of the protein, from very large motions of interdomain rotation to more localized side-chain conformational changes, and adaptation by the oligosaccharides as well.

Crystal structures of the maltodextrin/maltose-binding protein complexed with reduced oligosaccharides: flexibility of tertiary structure and ligand binding.,Duan X, Hall JA, Nikaido H, Quiocho FA J Mol Biol. 2001 Mar 9;306(5):1115-26. PMID:11237621<ref>PMID:11237621</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Maltose-binding protein|Maltose-binding protein]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Duan, X]]
[[Category: Hall, J A]]
[[Category: Nikaido, H]]
[[Category: Quiocho, F A]]
[[Category: Maltotetraitol]]
[[Category: Sugar binding protein]]
[[Category: Sugar-binding protein]]