In a large bowl, dissolve yeast in water. Add sugar, 2 tablespoons butter, shortening, egg, salt and 1 cup flour; beat until smooth. Stir in enough of the remaining flour to form a soft dough.
Turn onto a floured surface; knead until smooth and elastic, about 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and let rise in a warm place until doubled, about 1-1/4 hours.
Punch dough down. Turn onto a lightly floured surface. Roll into a 12-in. circle. Melt remaining butter; brush over the dough. Cut into 12 wedges. Roll up wedges from the wide end and curve to form crescents. Place pointed side down 2 in. apart on a greased baking sheet. Cover and let rise until doubled, about 45 minutes.
Bake at 375° for 8-10 minutes or until golden brown. Remove to a wire rack. Brush with additional melted butter if desired.