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| - | [[Image:2ehm.jpg|left|200px]]<br /><applet load="2ehm" size="350" color="white" frame="true" align="right" spinBox="true" | + | #REDIRECT [[3ah2]] This PDB entry is obsolete and replaced by 3ah2 |
| - | caption="2ehm, resolution 1.70Å" />
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| - | '''HA1 subcomponent of botulinum type C progenitor toxin complexed with N-acetylgalactosamine'''<br />
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| - | ==Overview==
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| - | Clostridium botulinum type C 16S progenitor toxin contains a hemagglutinin (HA) subcomponent, designated HA1, which appears to play an important role in the effective internalization of the toxin in gastrointestinal epithelial cells and in creating a broad specificity for the oligosaccharide structure that corresponds to various targets. In this study, using the recombinant protein fused to glutathione S-transferase, we investigated the binding specificity of the HA1 subcomponent to sugars and estimated the binding sites of HA1 based on X-ray crystallography and soaking experiments using various sugars. N-Acetylneuraminic acid, N-acetylgalactosamine, and galactose effectively inhibited the binding that occurs between glutathione S-transferase-HA1 and mucins, whereas N-acetylglucosamine and glucose did not inhibit it. The crystal structures of HA1 complex with N-acetylneuraminic acid, N-acetylgalactosamine, and galactose were also determined. There are two sugar-binding sites, sites I and II. Site I corresponds to the electron densities noted for all sugars and is located at the C-terminal beta-trefoil domain, while site II corresponds to the electron densities noted only for galactose. An aromatic amino acid residue, Trp176, at site I has a stacking interaction with the hexose ring of the sugars. On the other hand, there is no aromatic residue at site II; thus, the interaction with galactose seems to be poor. The double mutant W176A at site I and D271F at site II has no avidity for N-acetylneuraminic acid but has avidity for galactose. In this report, the binding specificity of botulinum C16S toxin HA1 to various sugars is demonstrated based on its structural features.
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| - | ==About this Structure==
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| - | 2EHM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Clostridium_botulinum Clostridium botulinum] with <scene name='pdbligand=NGA:'>NGA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Known structural/functional Site: <scene name='pdbsite=AC1:Nga+Binding+Site+For+Residue+B+2000'>AC1</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EHM OCA].
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| - | ==Reference==
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| - | Sugar-binding sites of the HA1 subcomponent of Clostridium botulinum type C progenitor toxin., Nakamura T, Tonozuka T, Ide A, Yuzawa T, Oguma K, Nishikawa A, J Mol Biol. 2008 Feb 22;376(3):854-67. Epub 2007 Dec 23. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=18178224 18178224]
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| - | [[Category: Clostridium botulinum]]
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| - | [[Category: Single protein]]
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| - | [[Category: Ide, A.]]
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| - | [[Category: Nakamura, T.]]
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| - | [[Category: Nishikawa, A.]]
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| - | [[Category: Oguma, K.]]
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| - | [[Category: Tonozuka, T.]]
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| - | [[Category: Yuzawa, T.]]
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| - | [[Category: NGA]]
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| - | [[Category: beta trefoil]]
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| - | [[Category: toxin]]
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| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:10:06 2008''
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