Dissolve yeast in warm water. Add salt and sugar to yeast mixture. Blend in flour and knead dough until smooth, about 7 to 8 minutes. Cover and let dough rise until double in bulk. Punch down. Cut dough into small pieces and roll into ropes. Twist ropes into pretzel shapes and place on greased cookie sheet. Using a pastry brush, bursh pretzels with egg and sprinkle with coarse salt. Allow pretzels to rise until almost double in bulk. Bake at 425 degrees F. for 10 to 15 minutes or until browned. Best if eaten immediately. If not, store in airtight container. Makes 12 6-inch pretzels.