Three‐dimensional structure of neurotoxin‐1 from Naja naja oxiana venom at 1.9 Å resolution

Abstract

Neurotoxin‐1 from Naja naja oxiana venom (NTX‐1) has been crystallized by vapor diffusion in sitting drops. The crystals have cell dimensions of a = 25.2 Å,b = 75.6 Å, c = 35.9 Å, and are in space group P2₁2₁2₁. Three‐dimensional data to 1.9 Å have been recorded by a Syntex P2₁ automatic diffractometer. The atomic structure of the toxin has been determined by molecular replacement using the α‐cobratoxin (α‐CTX) as the search model. The position of 534 non‐hydrogen protein atoms have been determined. The model contains 65 water molecules. Refinement has led to an R‐factor of 19.3% at 1.9 Å resolution. The secondary and tertiary structures of NTX‐1 have been analyzed and a comparison with structure of the α‐CTX has been made.