View source for 4urr


==Tailspike protein of Sf6 bacteriophage bound to Shigella flexneri O- antigen octasaccharide fragment==
<StructureSection load='4urr' size='340' side='right'caption='[[4urr]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4urr]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Shigella_virus_Sf6 Shigella virus Sf6]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4URR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4URR 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]] 1.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene>, <scene name='pdbligand=RAM:ALPHA-L-RHAMNOSE'>RAM</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=4urr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4urr OCA], [https://pdbe.org/4urr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4urr RCSB], [https://www.ebi.ac.uk/pdbsum/4urr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4urr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/FIBER_BPSFV FIBER_BPSFV] Non-covalently bound to the neck of the phage capsid and mediating attachment of the viral particle to host cell-surface polysaccharide. It displays endorhamnosidase enzymatic activity, hydrolyzing the alpha-1,3-O-glycosidic linkage between rhamnose and galactose of the O-antigen polysaccharide.<ref>PMID:18462681</ref> <ref>PMID:12424253</ref> <ref>PMID:6284</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Understanding interactions of bacterial surface polysaccharides with receptor protein scaffolds is important for the development of antibiotic therapies. The corresponding protein recognition domains frequently form low-affinity complexes with polysaccharides that are difficult to address with experimental techniques due to the conformational flexibility of the polysaccharide. In this work, we studied the tailspike protein (TSP) of the bacteriophage Sf6. Sf6TSP binds and hydrolyzes the high-rhamnose, serotype Y O-antigen polysaccharide of the Gram-negative bacterium Shigella flexneri (S. flexneri) as a first step of bacteriophage infection. Spectroscopic analyses and enzymatic cleavage assays confirmed that Sf6TSP binds long stretches of this polysaccharide. Crystal structure analysis and saturation transfer difference (STD) NMR spectroscopy using an enhanced method to interpret the data permitted the detailed description of affinity contributions and flexibility in an Sf6TSP-octasaccharide complex. Dodecasaccharide fragments corresponding to three repeating units of the O-antigen in complex with Sf6TSP were studied computationally by molecular dynamics simulations. They showed that distortion away from the low-energy solution conformation found in the octasaccharide complex is necessary for ligand binding. This is in agreement with a weak-affinity functional polysaccharide-protein contact that facilitates correct placement and thus hydrolysis of the polysaccharide close to the catalytic residues. Our simulations stress that the flexibility of glycan epitopes together with a small number of specific protein contacts provide the driving force for Sf6TSP-polysaccharide complex formation in an overall weak-affinity interaction system.

Bacteriophage Tailspikes and Bacterial O-Antigens as a Model System to Study Weak-Affinity Protein-Polysaccharide Interactions.,Kang Y, Gohlke U, Engstrom O, Hamark C, Scheidt T, Kunstmann S, Heinemann U, Widmalm G, Santer M, Barbirz S J Am Chem Soc. 2016 Jul 27;138(29):9109-18. doi: 10.1021/jacs.6b00240. Epub 2016 , Apr 25. PMID:27045683<ref>PMID:27045683</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4urr" style="background-color:#fffaf0;"></div>

==See Also==
*[[Tailspike protein 3D structures|Tailspike protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Shigella virus Sf6]]
[[Category: Barbirz S]]
[[Category: Gohlke U]]
[[Category: Heinemann U]]
[[Category: Seckler R]]