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2g7q

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Revision as of 07:49, 18 October 2017

Structure of the Light Chain of Botulinum Neurotoxin Serotype A Bound to Small Molecule Inhibitors

Structural highlights

2g7q is a 2 chain structure with sequence from "bacillus_botulinus"_van_ermengem_1896 "bacillus botulinus" van ermengem 1896. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Related:	2g7n, 2g7k, 2g7p
Gene:	botA, atx, bna ("Bacillus botulinus" van Ermengem 1896)
Activity:	Bontoxilysin, with EC number 3.4.24.69
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[BXA2_CLOBO] 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 the three isoforms 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 (By similarity).

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

Botulinum neurotoxin serotype A (BoNT/A, 1296 residues) is a zinc metalloprotease that cleaves SNAP25 to inhibit the fusion of neurotransmitter-carrying vesicles to the plasma membrane of peripheral neurons. BoNT/A is a disulfide-linked di-chain protein composed of an N-terminal, thermolysin-like metalloprotease light chain domain (LC/A, 448 residues) and a C-terminal heavy chain domain (848 residues) that can be divided into two subdomains, a translocation subdomain and a receptor binding subdomain. LC/A cleaves SNAP25 between residues Gln197-Arg198 and, unlike thermolysin, recognizes an extended region of SNAP25 for cleavage. The structure of a recombinant LC/A (1-425) treated with EDTA (No-Zn LC/A) was determined. The overall structure of No-Zn LC/A is similar to that reported for the holotoxin, except that it lacks the Zn ion, indicating that the role of Zn is catalytic not structural. In addition, structures of a noncatalytic mutant LC/A (Arg362Ala/Tyr365Phe) complexed with and without an inhibitor, ArgHX, were determined. The overall structure and the active site conformation for the mutant are the same as wild type. When the inhibitor binds to the active site, the carbonyl and N-hydroxyl groups form a bidentate ligand to the Zn ion and the arginine moiety binds to Asp369, suggesting that the inhibitor-bound structure mimics a catalytic intermediate with the Arg moiety binding at the P1' site. Consistent with this model, mutation of Asp369 to Ala decreases the catalytic activity of LC/A by approximately 600-fold, and the residual activity is not inhibited by ArgHX. These results provide new information on the reaction mechanism and insight into the development of strategies for small molecule inhibitors of BoNTs.

Light chain of botulinum neurotoxin serotype A: structural resolution of a catalytic intermediate.,Fu Z, Chen S, Baldwin MR, Boldt GE, Crawford A, Janda KD, Barbieri JT, Kim JJ Biochemistry. 2006 Jul 25;45(29):8903-11. PMID:16846233^[1]

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

References

↑ Fu Z, Chen S, Baldwin MR, Boldt GE, Crawford A, Janda KD, Barbieri JT, Kim JJ. Light chain of botulinum neurotoxin serotype A: structural resolution of a catalytic intermediate. Biochemistry. 2006 Jul 25;45(29):8903-11. PMID:16846233 doi:10.1021/bi060786z

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2g7q"

@@ Line 1: / Line 1: @@
 ==Structure of the Light Chain of Botulinum Neurotoxin Serotype A Bound to Small Molecule Inhibitors==
 <StructureSection load='2g7q' size='340' side='right' caption='[[2g7q]], [[Resolution|resolution]] 2.41&Aring;' scene=''>
@@ Line 7: / Line 8: @@
 <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 "Bacillus botulinus" van Ermengem 1896])</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Bontoxilysin Bontoxilysin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.24.69 3.4.24.69] </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=2g7q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2g7q OCA], [http://pdbe.org/2g7q PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2g7q RCSB], [http://www.ebi.ac.uk/pdbsum/2g7q 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=2g7q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2g7q OCA], [http://pdbe.org/2g7q PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2g7q RCSB], [http://www.ebi.ac.uk/pdbsum/2g7q PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2g7q ProSAT]</span></td></tr>
 </table>
 == Function ==

2g7q

From Proteopedia

Revision as of 07:49, 18 October 2017

Structure of the Light Chain of Botulinum Neurotoxin Serotype A Bound to Small Molecule Inhibitors

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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