Three-Dimensional Structure Determination of Botulinum Toxin.
Annual rept. 1 Aug 97-30 Jun 98
CALIFORNIA UNIV RIVERSIDE
Pagination or Media Count:
The immediate goals of the contract on the structure and function relationship of botulinum neurotoxin are 1 Determine the three-dimensional structure of botulinum neurotoxin at atomic resolution by x-ray crystallography. 2 Based on the structure of the neurotoxin, understand the toxins mechanism of action. We have accomplished the first goal of determining the three-dimensional structure of the 150 kD botulinum neurotoxin serotype A. The toxin is Y-shaped, with a very long alpha-helical translocation domain forming the backbone of the structure. The translocation domain is composed almost entirely of helices, 2 of which are 95 A in length and form a pseudo-coiled coil. The binding domain and catalytic domain are more globular in shape, located at two different ends of the translocation domain. The overall dimensions of the protein are 120 A x 80 A x 40 A. A complete description of the three- dimensional structure is described in the report the manuscript will he published in the September issue of Nature Structural Biology. We have recently collected data on an inhibitor complex and a receptor - complex. Refinement and analysis of the toxin with bound molecules will be completed within the next 12 months.