Preheat oven to 325. Grease 16 cup tube pan and dust pan with cake flour, tap out excess flour. Sift flour, baking soda and salt into medium bowl. Using electric mixer, beat butter in large bowl at medium speed until fluffy, gradually add sugar and beat until combined. Add eggs one at a time, beating just until combined after each addition. Beat in lemon juice and peel. Using rubber spatula, mix in dry ingredients. Mix in sour cream. Transfer batter to prepared pan. Bake cake until tester inserted near center comes out clean, about 1 hour 30 minutes. Let cake cool in pan on rack 15 minutes. Cut around cake in pan. Turn out cake. Carefully turn cake right side up on rack and cool completely. Sift powdered sugar over top of cake