1S0G

Crystal structure of botulinum neurotoxin type B apo form

Summary for 1S0G

• Entry DOI: 10.2210/pdb1s0g/pdb
• Related: 1EPW 1G9A 1S0B 1S0C 1S0D 1S0E 1S0F
• Descriptor: Botulinum neurotoxin type B (2 entities in total)
• Functional Keywords: botulinum, neurotoxin, ph, metals, toxin, hydrolase
• Biological source: Clostridium botulinum
• Cellular location: Botulinum neurotoxin B light chain: Secreted. Botulinum neurotoxin B heavy chain: Secreted: P10844
• Total number of polymer chains: 1
• Total formula weight: 150833.38

Authors

Eswaramoorthy, S.,Kumaran, D.,Keller, J.,Swaminathan, S. (deposition date: 2003-12-30, release date: 2004-03-16, Last modification date: 2024-10-30)

Primary citation

Eswaramoorthy, S.,Kumaran, D.,Keller, J.,Swaminathan, S.
Role of metals in the biological activity of Clostridium botulinum neurotoxins
Biochemistry, 43:2209-2216, 2004

PubMed Abstract: Clostridium botulinum neurotoxins are the most potent toxins to humans and cause paralysis by blocking neurotransmitter release at the presynaptic nerve terminals. The toxicity involves four steps, viz., binding to neuronal cells, internalization, translocation, and catalytic activity. While the catalytic activity is a zinc endopeptidase activity on the SNARE complex proteins, the translocation is believed to be a pH-dependent process allowing the translocation domain to change its conformation to penetrate the endosomal membrane. Here, we report the crystal structures of botulinum neurotoxin type B at various pHs and of an apo form of the neurotoxin, and discuss the role of metal ions and the effect of pH variation in the biological activity. Except for the perturbation of a few side chains, the conformation of the catalytic domain is unchanged in the zinc-depleted apotoxin, suggesting that zinc's role is catalytic. We have also identified two calcium ions in the molecule and present biochemical evidence to show that they play a role in the translocation of the light chain through the membrane.

PubMed: 14979717
DOI: 10.1021/bi035844k

Experimental method

X-RAY DIFFRACTION (2.6 Å)