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1qa2

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Revision as of 09:00, 25 December 2014

TAILSPIKE PROTEIN, MUTANT A334V

Structural highlights

1qa2 is a 1 chain structure with sequence from Enterobacteria phage p22. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[TSPE_BPP22] 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.^[1] ^[2]

Publication Abstract from PubMed

Four previously isolated mutations in Salmonella phage P22 tailspike protein were used to study the relationship between protein stability, folding, and function. Tailspike protein binds and hydrolyzes the repetitive O-antigen structure in Salmonella lipopolysaccharide. Four mutations (V331G, V331A, A334V, A334I) are known to increase the folding efficiency, and two of them (at position 331) also increase the thermal stability of the protein. Octasaccharides comprising two repeating units of the O-antigens from two different Salmonella strains were employed to analyze the receptor binding function of the mutant proteins. Their endorhamnosidase enzymatic activity was assayed with the aid of a fluorescence-labeled dodecasaccharide. Both V331A and V331G were found to strongly affect O-antigen binding. Octasaccharide binding affinities of the mutant proteins are reduced tenfold and 200-fold, corresponding to a loss of 17% and 36% of the standard free energy of binding, respectively. Both mutations at position 334 affected O-antigen binding only slightly (DeltaDeltaG(0)B approximately 1 kJ/mol), but these mutations reduce the thermal stability of the protein. The observed effects on the endoglycosidase activity are fully explained by the changes in substrate binding, suggesting that neither of the mutations affect the catalytic rate. Crystal structures of all four mutants were determined to a resolution of 2.0 A. Except for the partly or completely missing side-chain, no significant changes compared to the wild-type protein structure were found for the mutants at position 331, whereas a small but significant backbone displacement around the mutation site in A334V and A334I may explain the observed thermal destabilization.

Mutations improving the folding of phage P22 tailspike protein affect its receptor binding activity.,Baxa U, Steinbacher S, Weintraub A, Huber R, Seckler R J Mol Biol. 1999 Oct 29;293(3):693-701. PMID:10543960^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Weigele PR, Scanlon E, King J. Homotrimeric, beta-stranded viral adhesins and tail proteins. J Bacteriol. 2003 Jul;185(14):4022-30. PMID:12837775
↑ Andres D, Hanke C, Baxa U, Seul A, Barbirz S, Seckler R. Tailspike interactions with lipopolysaccharide effect DNA ejection from phage P22 particles in vitro. J Biol Chem. 2010 Nov 19;285(47):36768-75. doi: 10.1074/jbc.M110.169003. Epub, 2010 Sep 3. PMID:20817910 doi:http://dx.doi.org/10.1074/jbc.M110.169003
↑ Baxa U, Steinbacher S, Weintraub A, Huber R, Seckler R. Mutations improving the folding of phage P22 tailspike protein affect its receptor binding activity. J Mol Biol. 1999 Oct 29;293(3):693-701. PMID:10543960 doi:10.1006/jmbi.1999.3165

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1qa2"

@@ Line 5: / Line 5: @@
 </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=1qa2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qa2 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1qa2 RCSB], [http://www.ebi.ac.uk/pdbsum/1qa2 PDBsum]</span></td></tr>
 </table>
+== Function ==
+[[http://www.uniprot.org/uniprot/TSPE_BPP22 TSPE_BPP22]] 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:12837775</ref> <ref>PMID:20817910</ref>
 <div style="background-color:#fffaf0;">
 == Publication Abstract from PubMed ==
@@ Line 18: / Line 20: @@
 </StructureSection>
 [[Category: Enterobacteria phage p22]]
-[[Category: Baxa, U.]]
+[[Category: Baxa, U]]
-[[Category: Huber, R.]]
+[[Category: Huber, R]]
-[[Category: Seckler, R.]]
+[[Category: Seckler, R]]
-[[Category: Steinbacher, S.]]
+[[Category: Steinbacher, S]]
-[[Category: Weintraub, A.]]
+[[Category: Weintraub, A]]
 [[Category: Viral protein-receptor complex]]
 [[Category: Virus/viral protein]]

1qa2

From Proteopedia

Revision as of 09:00, 25 December 2014

TAILSPIKE PROTEIN, MUTANT A334V

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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