Heat oven to 375°F. In medium bowl, combine 1 cup flour, 1 tablespoon sugar, 1 teaspoon lemon peel and salt; mix well. With pastry blender or fork, cut in margarine until mixture resembles coarse crumbs. With fork, stir in 1 egg and enough water for mixture to form a ball. Press in bottom and up sides of 9 1/2 or 10-inch tart pan with removable bottom. Bake at 375°F. for 15 minutes.