4xr6: Difference between revisions
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==Tailspike protein double mutant D339A/E372Q of E. coli bacteriophage HK620 in complex with hexasaccharide== | ==Tailspike protein double mutant D339A/E372Q of E. coli bacteriophage HK620 in complex with hexasaccharide== | ||
<StructureSection load='4xr6' size='340' side='right' caption='[[4xr6]], [[Resolution|resolution]] 1.78Å' scene=''> | <StructureSection load='4xr6' size='340' side='right'caption='[[4xr6]], [[Resolution|resolution]] 1.78Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4xr6]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XR6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4XR6 FirstGlance]. <br> | <table><tr><td colspan='2'>[[4xr6]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bphk6 Bphk6]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XR6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4XR6 FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=FMT:FORMIC+ACID'>FMT</scene>, <scene name='pdbligand=GLA:ALPHA+D-GALACTOSE'>GLA</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NDG:2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE'>NDG</scene>, <scene name='pdbligand=RAM:ALPHA-L-RHAMNOSE'>RAM</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></td></tr> | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=FMT:FORMIC+ACID'>FMT</scene>, <scene name='pdbligand=GLA:ALPHA+D-GALACTOSE'>GLA</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NDG:2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE'>NDG</scene>, <scene name='pdbligand=RAM:ALPHA-L-RHAMNOSE'>RAM</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></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=4xr6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xr6 OCA], [http://pdbe.org/4xr6 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4xr6 RCSB], [http://www.ebi.ac.uk/pdbsum/4xr6 PDBsum]</span></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=4xr6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xr6 OCA], [http://pdbe.org/4xr6 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4xr6 RCSB], [http://www.ebi.ac.uk/pdbsum/4xr6 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4xr6 ProSAT]</span></td></tr> | ||
</table> | </table> | ||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
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__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: Bphk6]] | |||
[[Category: Large Structures]] | |||
[[Category: Barbirz, S]] | [[Category: Barbirz, S]] | ||
[[Category: Broeker, N K]] | [[Category: Broeker, N K]] | ||
Revision as of 02:39, 6 June 2019
Tailspike protein double mutant D339A/E372Q of E. coli bacteriophage HK620 in complex with hexasaccharideTailspike protein double mutant D339A/E372Q of E. coli bacteriophage HK620 in complex with hexasaccharide
Structural highlights
Publication Abstract from PubMedBacteriophage HK620 recognizes and cleaves the Oantigen polysaccharide of E. coli serogroup O18A1 with its tailspike protein (TSP). HK620TSP binds hexasaccharide fragments with low affinity, but single amino acid exchanges generated a set of high-affinity mutants with submicromolar dissociation constants. Isothermal titration calorimetry showed that only small amounts of heat were released upon complex formation via a large number of direct and solvent mediated hydrogen bonds between carbohydrate and protein. At room temperature association was both enthalpy- and entropy-driven emphasizing major solvent rearrangements upon complex formation. Crystal structure analysis showed identical protein and sugar conformers in the TSP complexes regardless of their hexasaccharide affinity. Only in one case a TSP mutant bound a different hexasaccharide conformer. The extended sugar binding site could be dissected in two regions: Firstly, a hydrophobic pocket at the reducing end with minor affinity contributions. Access to this site could be blocked by a single aspartate to asparagine exchange without major loss in hexasaccharide affinity. Secondly, a region where specific exchange of glutamate for glutamine created a site for an additional water molecule. Side chain rearrangements upon sugar binding led to desolvation and additional hydrogen bonding which define this region of the binding site as the high affinity scaffold. Single amino acid exchange in bacteriophage HK620 tailspike protein results in thousand-fold increase of its oligosaccharide affinity.,Broeker NK, Gohlke U, Muller JJ, Uetrecht C, Heinemann U, Seckler R, Barbirz S Glycobiology. 2012 Aug 24. PMID:22923442[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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