In a large bowl, combine 1-1/2 cups flour, sugar, yeast and salt. In a small saucepan, heat the sour cream, water and 2 tablespoons butter to 120°-130°; add to dry ingredients. Beat on medium speed for 2 minutes. Add egg and 1/2 cup flour; beat 2 minutes longer. Stir in enough 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 the top. Cover and let rise in a warm place until doubled, about 1 hour.
Punch dough down. Turn onto a lightly floured surface; divide into 12 pieces. Shape each into a ball. Place in a greased 13-in. x 9-in. baking pan. Cover and let rise until doubled, about 30 minutes.
Bake at 375° for 25-30 minutes or until golden brown. Melt remaining butter; brush over rolls. Remove from pan to a wire rack.