Figure 4

Surface conservation of squid neuronal syntaxin Two projections of squid neuronal syntaxin related by an 180° rotation are shown. In the middle panels B and E, shades of green indicate the degree of amino acid conservation within distantly related neuronal syntaxins, white, no conservation, and dark green, absolute conservation. The surface conservation score was calculated with ESPript based on the sequence alignment in Figure 3[60]. Conserved surface residues in the putative Munc13 binding region are labeled. On the right (panels C and F), rat syntaxin 1A residues involved in intramolecular closed conformation and nSec1 interactions are shown for comparison in turquoise and orange, respectively. Ribbon representations of syntaxin using rainbow color-coding are shown on the left for orientation (panels A and D).