The three-dimensional structure of notexin, a presynaptic neurotoxic phospholipase A2: B. Westerlund,1D. Eaker,1P. Nordlund,2U. Uhlin3 and H. Eklund3 (1Department of Biochemistry, Uppsala University, Biomedical Center, Box 576, S-751 23 Uppsala, Sweden; 2Department of Molecular Biology, University of Stockholm, S-106 91 Stockholm, Sweden; and 3Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Center, S-751 49 Uppsala, Sweden)