PDBsum entry 3obt

Hydrolase

PDB id: 3obt

Contents

Protein chain

412 a.a. *

Ligands

SLB

GOL ×11

Waters ×317

* Residue conservation analysis

PDB id:

3obt

Name:

Hydrolase

Title:

Crystal structure of botulinum neurotoxin serotype d ligand binding domain in complex with n-acetylneuraminic acid

Structure:

Botulinum neurotoxin type d. Chain: a. Fragment: ligand binding domain. Synonym: bont/d, bontoxilysin-d, botulinum neurotoxin d light chain, botulinum neurotoxin d heavy chain. Engineered: yes

Source:

Clostridium botulinum. Organism_taxid: 1491. Gene: botd. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.00Å R-factor: 0.174 R-free: 0.221

Authors:

K.K.Lee,Y.Zong,R.Jin

Key ref:

J.Strotmeier et al. (2010). Botulinum neurotoxin serotype D attacks neurons via two carbohydrate-binding sites in a ganglioside-dependent manner. Biochem J, 431, 207-216. PubMed id: 20704566

Date:

09-Aug-10 Release date: 08-Sep-10

Protein chain

P19321  (BXD_CBDP) -  Botulinum neurotoxin type D from Clostridium botulinum D phage

Seq: 1276 a.a.

Struc: 412 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.4.24.69 - bontoxilysin.
• Reaction: Limited hydrolysis of proteins of the neuroexocytosis apparatus, synaptobrevins, SNAP25 or syntaxin. No detected action on small molecule substrates.
• Cofactor: Zn(2+)

Biochem J 431:207-216 (2010)

PubMed id: 20704566

Botulinum neurotoxin serotype D attacks neurons via two carbohydrate-binding sites in a ganglioside-dependent manner.

J.Strotmeier, K.Lee, A.K.Völker, S.Mahrhold, Y.Zong, J.Zeiser, J.Zhou, A.Pich, H.Bigalke, T.Binz, A.Rummel, R.Jin.

ABSTRACT

The extraordinarily high toxicity of botulinum neurotoxins primarily results from their specific binding and uptake into neurons. At motor neurons, the seven BoNT (botulinum neurotoxin) serotypes A-G inhibit acetylcholine release leading to flaccid paralysis. Uptake of BoNT/A, B, E, F and G requires a dual interaction with gangliosides and the synaptic vesicle proteins synaptotagmin or SV2 (synaptic vesicle glycoprotein 2), whereas little is known about the cell entry mechanisms of the serotypes C and D, which display the lowest amino acid sequence identity compared with the other five serotypes. In the present study we demonstrate that the neurotoxicity of BoNT/D depends on the presence of gangliosides by employing phrenic nerve hemidiaphragm preparations derived from mice expressing the gangliosides GM3, GM2, GM1 and GD1a, or only GM3 [a description of our use of ganglioside nomenclature is given in Svennerholm (1994) Prog. Brain Res. 101, XI-XIV]. High-resolution crystal structures of the 50 kDa cell-binding domain of BoNT/D alone and in complex with sialic acid, as well as biological analyses of single-site BoNT/D mutants identified two carbohydrate-binding sites. One site is located at a position previously identified in BoNT/A, B, E, F and G, but is lacking the conserved SXWY motif. The other site, co-ordinating one molecule of sialic acid, resembles the second ganglioside-binding pocket (the sialic-acid-binding site) of TeNT (tetanus neurotoxin).