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| | ==Structure of the C. botulinum neurotoxin serotype A with Zn2+ cofactor bound== | | ==Structure of the C. botulinum neurotoxin serotype A with Zn2+ cofactor bound== |
| - | <StructureSection load='3bon' size='340' side='right' caption='[[3bon]], [[Resolution|resolution]] 1.20Å' scene=''> | + | <StructureSection load='3bon' size='340' side='right'caption='[[3bon]], [[Resolution|resolution]] 1.20Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[3bon]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Clostridium_botulinum Clostridium botulinum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BON OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3BON FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[3bon]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Clostridium_botulinum Clostridium botulinum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BON OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3BON FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</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]] 1.2Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3bok|3bok]], [[3boo|3boo]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">BOTA, ATX, BNA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1491 Clostridium botulinum])</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=3bon FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3bon OCA], [https://pdbe.org/3bon PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3bon RCSB], [https://www.ebi.ac.uk/pdbsum/3bon PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3bon ProSAT]</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=3bon FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3bon OCA], [http://pdbe.org/3bon PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3bon RCSB], [http://www.ebi.ac.uk/pdbsum/3bon PDBsum]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/BXA1_CLOBH BXA1_CLOBH] Inhibits acetylcholine release. The botulinum toxin binds with high affinity to peripheral neuronal presynaptic membrane to the secretory vesicle protein SV2. It binds directly to the largest luminal loop of SV2A, SV2B and SV2C. It is then internalized by receptor-mediated endocytosis. The C-terminus of the heavy chain (H) is responsible for the adherence of the toxin to the cell surface while the N-terminus mediates transport of the light chain from the endocytic vesicle to the cytosol. After translocation, the light chain (L) hydrolyzes the 197-Gln-|-Arg-198 bond in SNAP-25, thereby blocking neurotransmitter release. Inhibition of acetylcholine release results in flaccid paralysis, with frequent heart or respiratory failure. |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/bo/3bon_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/bo/3bon_consurf.spt"</scriptWhenChecked> |
| | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
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| | ==See Also== | | ==See Also== |
| - | *[[Botulinum neurotoxin|Botulinum neurotoxin]] | + | *[[Botulinum neurotoxin 3D structures|Botulinum neurotoxin 3D structures]] |
| - | *[[Clostridium botulinum neurotoxin serotype A light chain|Clostridium botulinum neurotoxin serotype A light chain]]
| + | |
| | == References == | | == References == |
| | <references/> | | <references/> |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Clostridium botulinum]] | | [[Category: Clostridium botulinum]] |
| - | [[Category: Allen, K N]] | + | [[Category: Large Structures]] |
| - | [[Category: Silvaggi, N R]] | + | [[Category: Allen KN]] |
| - | [[Category: Botulinum]] | + | [[Category: Silvaggi NR]] |
| - | [[Category: Metalloprotease]]
| + | |
| - | [[Category: Neurotoxin]]
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| - | [[Category: Toxin]]
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| Structural highlights
Function
BXA1_CLOBH Inhibits acetylcholine release. The botulinum toxin binds with high affinity to peripheral neuronal presynaptic membrane to the secretory vesicle protein SV2. It binds directly to the largest luminal loop of SV2A, SV2B and SV2C. It is then internalized by receptor-mediated endocytosis. The C-terminus of the heavy chain (H) is responsible for the adherence of the toxin to the cell surface while the N-terminus mediates transport of the light chain from the endocytic vesicle to the cytosol. After translocation, the light chain (L) hydrolyzes the 197-Gln-|-Arg-198 bond in SNAP-25, thereby blocking neurotransmitter release. Inhibition of acetylcholine release results in flaccid paralysis, with frequent heart or respiratory failure.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The Clostridium botulinum neurotoxin serotype A light chain (BoNT/A-LC) is a Zn(II)-dependent metalloprotease that blocks the release of acetylcholine at the neuromuscular junction by cleaving SNAP-25, one of the SNARE proteins required for exocytosis. Because of the potential for use of the toxin in bioterrorism and the increasingly widespread application of the toxin in the medical field, there is significant interest in the development of small-molecule inhibitors of the metalloprotease. Efforts to design such inhibitors have not benefited from knowledge of how peptides bind to the active site since the enzyme-peptide structures available previously either were not occupied in the vicinity of the catalytic Zn(II) ion or did not represent the product of SNAP-25 substrate cleavage. Herein we report the 1.4 A-resolution X-ray crystal structure of a complex between the BoNT/A-LC and the inhibitory peptide N-Ac-CRATKML, the first structure of the light chain with an inhibitory peptide bound at the catalytic Zn(II) ion. The peptide is bound with the Cys S gamma atom coordinating the metal ion. Surprisingly, the cysteine sulfur is oxidized to the sulfenic acid form. Given the unstable nature of this species in solution, is it likely that oxidation occurs on the enzyme. In addition to the peptide-bound structure, we report two structures of the unliganded light chain with and without the Zn(II) cofactor bound at 1.25 and 1.20 A resolution, respectively. The two structures are nearly identical, confirming that the Zn(II) ion plays a purely catalytic role. Additionally, the structure of the Zn(II)-bound uncomplexed enzyme allows identification of the catalytic water molecule and a second water molecule that occupies the same position as the peptidic oxygen in the tetrahedral intermediate. This observation suggests that the enzyme active site is prearranged to stabilize the tetrahedral intermediate of the protease reaction.
Catalytic features of the botulinum neurotoxin a light chain revealed by high resolution structure of an inhibitory peptide complex.,Silvaggi NR, Wilson D, Tzipori S, Allen KN Biochemistry. 2008 May 27;47(21):5736-45. Epub 2008 May 6. PMID:18457419[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Silvaggi NR, Wilson D, Tzipori S, Allen KN. Catalytic features of the botulinum neurotoxin a light chain revealed by high resolution structure of an inhibitory peptide complex. Biochemistry. 2008 May 27;47(21):5736-45. Epub 2008 May 6. PMID:18457419 doi:10.1021/bi8001067
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