Figure 1.

The NV mutation in Munc18-1 and Munc18-2 diminishes syntaxin1 binding. A, Structural model of Munc18-1 in complex with the closed conformation of syntaxin1 (Misura et al., 2000) (Protein Data Bank code 1DN1). The mutated residues of Munc18-1 NV are shown in orange filled representation. B, Sequence alignment of a short fragment of Munc18-1 and Munc18-2. Arrowheads point to the mutated residues in the NV mutants. C, GST–syntaxin1 binding of Munc18-1 and Munc18-2 (WT) and their NV mutants. D, Mean ± SEM binding of Munc18-1 NV and Munc18-2 NV to syntaxin1 as a fraction of WT binding. n = 4 experiments.