3DDA

Crystal structure of the catalytic domain of Botulinum neurotoxin serotype a with a snap-25 peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.183 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Substrate binding mode and its implication on drug design for botulinum neurotoxin A

Kumaran, D.Rawat, R.Ahmed, S.A.Swaminathan, S.

(2008) Plos Pathog. 4: e1000165-e1000165

  • DOI: 10.1371/journal.ppat.1000165
  • Primary Citation of Related Structures:  3DDB

  • PubMed Abstract: 
  • The seven antigenically distinct serotypes of Clostridium botulinum neurotoxins, the causative agents of botulism, block the neurotransmitter release by specifically cleaving one of the three SNARE proteins and induce flaccid paralysis. The Centers f ...

    The seven antigenically distinct serotypes of Clostridium botulinum neurotoxins, the causative agents of botulism, block the neurotransmitter release by specifically cleaving one of the three SNARE proteins and induce flaccid paralysis. The Centers for Disease Control and Prevention (CDC) has declared them as Category A biowarfare agents. The most potent among them, botulinum neurotoxin type A (BoNT/A), cleaves its substrate synaptosome-associated protein of 25 kDa (SNAP-25). An efficient drug for botulism can be developed only with the knowledge of interactions between the substrate and enzyme at the active site. Here, we report the crystal structures of the catalytic domain of BoNT/A with its uncleavable SNAP-25 peptide (197)QRATKM(202) and its variant (197)RRATKM(202) to 1.5 A and 1.6 A, respectively. This is the first time the structure of an uncleavable substrate bound to an active botulinum neurotoxin is reported and it has helped in unequivocally defining S1 to S5' sites. These substrate peptides make interactions with the enzyme predominantly by the residues from 160, 200, 250 and 370 loops. Most notably, the amino nitrogen and carbonyl oxygen of P1 residue (Gln197) chelate the zinc ion and replace the nucleophilic water. The P1'-Arg198, occupies the S1' site formed by Arg363, Thr220, Asp370, Thr215, Ile161, Phe163 and Phe194. The S2' subsite is formed by Arg363, Asn368 and Asp370, while S3' subsite is formed by Tyr251, Leu256, Val258, Tyr366, Phe369 and Asn388. P4'-Lys201 makes hydrogen bond with Gln162. P5'-Met202 binds in the hydrophobic pocket formed by the residues from the 250 and 200 loop. Knowledge of interactions between the enzyme and substrate peptide from these complex structures should form the basis for design of potent inhibitors for this neurotoxin.


    Organizational Affiliation

    Biology Department, Brookhaven National Laboratory, Upton, New York, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Botulinum neurotoxin A light chain
A
430Clostridium botulinumGene Names: botA (atx, bna)
EC: 3.4.24.69
Find proteins for P10845 (Clostridium botulinum)
Go to UniProtKB:  P10845
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Synaptosomal-associated protein 25
B
7Homo sapiensGene Names: SNAP25 (SNAP)
Find proteins for P60880 (Homo sapiens)
Go to Gene View: SNAP25
Go to UniProtKB:  P60880
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
B
NON-POLYMERH2 N

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.183 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 49.143α = 90.00
b = 66.192β = 99.09
c = 64.818γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
CBASSdata collection
HKL-2000data scaling
CNSphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-09-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance