4khz
From Proteopedia
(Difference between revisions)
| Line 4: | Line 4: | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4khz]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_DH1 Escherichia coli DH1] and [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4KHZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4KHZ FirstGlance]. <br> | <table><tr><td colspan='2'>[[4khz]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_DH1 Escherichia coli DH1] and [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4KHZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4KHZ FirstGlance]. <br> | ||
| - | </td></tr><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>, <scene name='pdbligand=PGV:(1R)-2-{[{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PALMITOYLOXY)METHYL]ETHYL+(11E)-OCTADEC-11-ENOATE'>PGV</scene>, <scene name='pdbligand=PRD_900009:alpha-maltotriose'>PRD_900009</scene>, <scene name='pdbligand=PRD_900010:alpha-maltotetraose'>PRD_900010</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.9Å</td></tr> |
| + | <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>, <scene name='pdbligand=PGV:(1R)-2-{[{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PALMITOYLOXY)METHYL]ETHYL+(11E)-OCTADEC-11-ENOATE'>PGV</scene>, <scene name='pdbligand=PRD_900009:alpha-maltotriose'>PRD_900009</scene>, <scene name='pdbligand=PRD_900010:alpha-maltotetraose'>PRD_900010</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=4khz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4khz OCA], [https://pdbe.org/4khz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4khz RCSB], [https://www.ebi.ac.uk/pdbsum/4khz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4khz ProSAT]</span></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=4khz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4khz OCA], [https://pdbe.org/4khz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4khz RCSB], [https://www.ebi.ac.uk/pdbsum/4khz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4khz ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
[https://www.uniprot.org/uniprot/MALE_ECOLI MALE_ECOLI] Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides. | [https://www.uniprot.org/uniprot/MALE_ECOLI MALE_ECOLI] Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides. | ||
| - | <div style="background-color:#fffaf0;"> | ||
| - | == Publication Abstract from PubMed == | ||
| - | ATP-binding cassette (ABC) transporters are molecular pumps that harness the chemical energy of ATP hydrolysis to translocate solutes across the membrane. The substrates transported by different ABC transporters are diverse, ranging from small ions to large proteins. Although crystal structures of several ABC transporters are available, a structural basis for substrate recognition is still lacking. For the Escherichia coli maltose transport system, the selectivity of sugar binding to maltose-binding protein (MBP), the periplasmic binding protein, does not fully account for the selectivity of sugar transport. To obtain a molecular understanding of this observation, we determined the crystal structures of the transporter complex MBP-MalFGK2 bound with large malto-oligosaccharide in two different conformational states. In the pretranslocation structure, we found that the transmembrane subunit MalG forms two hydrogen bonds with malto-oligosaccharide at the reducing end. In the outward-facing conformation, the transmembrane subunit MalF binds three glucosyl units from the nonreducing end of the sugar. These structural features explain why modified malto-oligosaccharides are not transported by MalFGK2 despite their high binding affinity to MBP. They also show that in the transport cycle, substrate is channeled from MBP into the transmembrane pathway with a polarity such that both MBP and MalFGK2 contribute to the overall substrate selectivity of the system. | ||
| - | |||
| - | Structural basis for substrate specificity in the Escherichia coli maltose transport system.,Oldham ML, Chen S, Chen J Proc Natl Acad Sci U S A. 2013 Oct 21. PMID:24145421<ref>PMID:24145421</ref> | ||
| - | |||
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| - | </div> | ||
| - | <div class="pdbe-citations 4khz" style="background-color:#fffaf0;"></div> | ||
==See Also== | ==See Also== | ||
*[[Maltose-binding protein 3D structures|Maltose-binding protein 3D structures]] | *[[Maltose-binding protein 3D structures|Maltose-binding protein 3D structures]] | ||
| - | == References == | ||
| - | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Current revision
Crystal structure of the maltose-binding protein/maltose transporter complex in an pre-translocation conformation bound to maltoheptaose
| |||||||||||
