Place dough ball in a greased bowl, turning to coat all sides. Cover bowl with a clean towel and set aside in a warm place about 1 hour, until dough has doubled. Punch down dough and remove from bowl. Cut dough into three equal pieces and shape each into a 10-inch strip. Crimp strips together at top and braid.
Tuck ends under.
If desired, beat egg with 1 tablespoon water and paint top of bread. Cover bread with the towel and let rise for 30 minutes. Preheat oven to 350 degrees. Bake bread for 40 minutes, until it sounds hollow when lightly tapped on the bottom.